KR980011640A - CRT improvement or matrixing - Google Patents

Abstract

A photoresist coating is applied to the inner surface of the glass plate of the cathode ray tube (CRT) using a light etching method in the form of a matrix surrounded by a respective photo resist layer with a large number of clear regions. In conjunction with its encapsulating photoresist, which provides improved video image color contrast, the fluorescent material that yields the three primary colors of red, green, and blue is placed in the clear zone. After placement on a glass substrate, the light sensitive photoresist coating is cured with ultraviolet (UV) light, which is characterized as having maximum intensity at a given wavelength. The photosensitive component of the photoresist coating is selected to have its maximum photoelectric sensitivity at the wavelength of maximum intensity of the UV light source to provide a high quality hump matrix for good video image color contrast. The photosensitive component is characterized as comprising a ketone group.

Description

Improved black matting of CRT

Since this is a trivial issue, I did not include the contents of the text.

Figure 1 is a longitudinal cross-sectional view of a CRT incorporating a photoresist coating on the inner surface of its glass plate according to the principles of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a cathode ray tube (CRT) type image display device, and more particularly to an improved photoresist for coating the inner surface of a glass plate of a CRT for high quality image color contrast.

Photolithography is a widely used method for screening CRTs, glass plates or face plates to produce red, green, and blue primary fluorescent materials.

This basic projection surface printing technique typically involves exposure of a light sensitive colloid such that the exposed areas are not dissolved and remain after development. In order to improve the color contrast, prior to the application of the fluorescent material screening, a lithographic printing method is used to calculate the pattern on the display surface, and the areas not occupied by the color fluorescent materials are processed in the process known as black matting, Lt; / RTI > The fluorescent substance screening process involves the application of photoresist applied to the inner surface of the display surface.

The photoresist typically comprises polyvinylpyrrolidone (PVP), 4,4-diazidostilbene-2,2 disulfonic acid, disodium salt and water. Adhesion of the photoresist to the CRT glass display surface is always a problem, which leads to a reduction in production yield. To overcome this problem, polyvinyl alcohol (PVA) is added to the photoresist material. After application to the inner surface of the CRT, the photoresist material is irradiated with ultraviolet (UV) light of a given wavelength that activates the photosensitive element to cure the photoresist layer. Another problem encountered with prior art photoresist materials is the appearance of UV light to cure the photosensitive elements of the photoresist and the photoresist. Generally, a mercury UV light source is used which exhibits maximum intensity of 365 nm, 405 nm, and 440 nm for the black matrix application of the description. However, the maximum photoelectric sensitivity of the photosensitive component of the photoresist, i.e., disodium 4,4-diazidostilbene 2,2-disulfonate is 335 nm. This difference between the maximum intensity wavelength of the projected UV light and the maximum photoelectric sensitivity of the photoresist material leads to an increase in non-uniformity and irregularity of the photoresist coating, which reduces the contrast of the projection screen.

The present invention provides a photosensitive element of a photoresist coating with an improved photoelectric sensitivity to UV light that is projected onto a photoresist coating, in order to activate and cure the coating which provides a high screen image color contrast to the display panel To overcome the limitations of the prior art mentioned above.

Hereinafter, preferred embodiments of the present invention will be described in detail. Referring to FIG. 1, there is shown a longitudinal section of a color CRT 10 incorporating a photoresist coating 24 of a phosphor base in accordance with the principles of the present invention. In the following description, the terms dispaly screen, display panel, and faceplate are used interchangeably. The CRT 10 includes a sealed glass envelope 12 having a front faceplate or display screen 14, a rear neck portion 18 and an intermediate funnel portion 16 therebetween . The photoresist coating 24 includes a plurality of individual phosphor deposits, or elements, to produce a video image on a display panel when an electron beam is emitted thereto. The color CRT 10 includes a set of electron beams 22 focused toward the glass plate 14 of the CRT. A plurality of electron guns 20 arranged in a line are arranged in the neck 18 of the glass envelope 12 of the CRT so as to direct the electron beams 22 to the sign board 14. [ The electron beams 22 are biased vertically and horizontally all at once across the photoresist coating 24 of the phosphor base by a magnetic deflection yoke, not shown, for simplicity. A shadow mask 26 having a plurality of sub-electron beams passing through the holes 26a and the skirt portion 28 around the periphery thereof is spaced apart from the phosphor screen 24. The shadow mask skirt portion 28 is firmly attached to the shadow mask mounting fixture 30 around the shadow mask. The shadow mask mounting fixture 30 is attached to the inner surface of the glass envelope 12 of the CRT and includes a conventional attachment and positioning structure, such as a masking frame and attachment spring, good. The shadow mask attaching fixture 30 may be attached to the inner surface of the glass envelope 12 of the CRT and the shadow mask 26 may be attached to the attachment fixture by conventional means such as a weld or glass foundation frit good. An antistatic / antireflection film 32 is disposed on the outer surface of the display screen 14.

As described above, prior art photoresist materials include PVA, PVP, and light sensitive sodium salts such as disodium 4,4-diazidstylbenzene 2,2'-disulfonate of the formula .

This sodium salt exhibits maximum photoelectric sensitivity at 335 nm. UV light sources typically used to cure photoresist materials are mercury light sources having maximum intensity at 365 nm, 405 nm, and 440 nm. At the wavelength of the maximum intensity of the UV light source, the maximum photoelectron sensitivity of the disodium salt is not produced, so the quality of the photoresist coating hardens and the color contrast of the video image provided on the display plate is scarred.

In accordance with the present invention, a compound containing a ketone group is used in place of the disodium salt of the prior art such as disodium 4,4-diazidstylbenzene 2,2'-disulfonate for good photoelectric sensitivity. An example of a ketone group that replaces a compound used as a photosensitive component of a photoresist material is as follows.

The listed compounds are merely examples of photoresist materials that provide good photoelectric sensitivity in accordance with the present invention and do not imply the entire Kenton-based photosensitive compound used in photoresist materials in accordance with the present invention. The optimum wavelength of 365 nm by the black matting method is 365 nm, and the prior art photosensitive compound disodium 4,4-diazidstylbenzene 2,2'-disulfonate has the maximum photoelectric sensitivity at 335 nm and is preferable for lithography I do not. The present invention incorporates a ketone group (-C = O) that changes its sensitivity to light to the long wavelength in the photosensitive component of the photoresist material. Listed in parentheses following the photosensitizing component of each of the above listed photoresist materials is its intrinsic wavelength for maximum photoelectro sensitivity to the projection UV light. It can be seen from the maximum photovoltage wavelengths listed above that each of the compounds listed above provides a higher sensitivity than the prior art photosensitive compounds utilized in photoresist materials. In a first embodiment, the photosensitive compound is 1-30 wt% of the total black matrixing solution comprising PVA, PVP and VA-VP copolymer.

Claims (9)

A photoresist coating disposed on an inner surface of a glass image display plate, the photoresist coating comprising a photosensitive element sensitive to ultraviolet (UV) light projected thereto for curing the photoresist coating, Characterized in that the UV light is characterized as having a maximum intensity at a given wavelength such that the light sensitive component has a ketone group added to said photoresist coating and wherein said photosensitive component with said ketone group has the highest sensitivity at the maximum intensity of the projected UV light . The positive photosensitive composition as claimed in claim 1, wherein the photosensitive component is disodium 2,2- (1,5, -penta-3-yl-1,4-dienyl) bis (5-azidobenzenesulfonate); 2,6-di (p-azidobenzal) -cyclohexanone; 2,6-di (p-azidobenzal) -4-methyl-cyclohexanone; 2,5 bis- (sodium 4-azido-2-sulfobenzal) cyclopentanone; And 4,4'-diazid benzalacetone-2,2'-disulfonic acid disodium salt. 3. The improved photoresist composition of claim 2, wherein the photosensitive component is in the range of 1-30 wt% of the photoresist coating. 3. The composition of claim 2, wherein the UV light has a maximum intensity at 365 nm and is selected from the group consisting of disodium 2,2- (1,5-penta-3-yl-1,4-dienyl) bis (5-azidobenzenesulfonate) ; 2,6-di (p-azidobenzal) -cyclohexanone; 2,6-di (p-azidobenzal) -4-methyl-cyclohexanone; 2,5, bis- (sodium 4-azido-2-sulfobenzal) cyclopentanone; And 4,4'-diazid benzalacetone-2,2'-disulfonic acid disodium salt have maximum sensitivities at 360 nm, 356 nm, 356 nm, 380 nm, and 360 nm, respectively. A method of preparing a photoresist coating for use on an inner surface of a glass image display plate, comprising: forming a coating solution of polyvinylpyrrolidone (PVP) and water; Adding polyvinyl alcohol (PVA) to the coating solution to improve adhesion of the coating solution to a glass image display plate; And adding a photosensitive disodium salt having a ketone group to the coating solution to render the coating solution susceptible to ultraviolet (UV) light projected thereon for curing the photoresist coating, Characterized by having a maximum intensity at a given wavelength and wherein the ketone provides substantially ultimate sensitivity to UV light to the coating solution at the given wavelength. 6. The composition of claim 5, wherein the dinatom is 2,2- (1,5-penta-3-yl-1,4-dienyl) bis (5-azidobenzenesulfonate); 2,6-di (p-azidobenzal) -cyclohexanone; 2,6-di (p-azidobenzal) -4-methyl-cyclohexanone; 2,5, bis- (sodium 4-azido-2-sulfobenzal) cyclopentanone; And a photosensitive disodium salt selected from the group consisting of 4,4'-diazid benzalacetone-2,2'-disulfonic acid disodium salt. A coating for use on the inner surface of a cathode ray tube glass face plate, comprising: a solution comprising polyvinylpyrrolidone (PVP) in water; Polyvinyl alcohol (PVA) for adhesion of the solution to the inner surface of a cathode ray tube glass faceplate; And a photosensitive disodium salt to render said solution susceptible to ultraviolet (UV) light projected thereon for curing the coating, said tactical UV light having a maximum intensity at a given wavelength, said disodium salt Wherein the coating comprises a ketone group that provides the coating with the highest sensitivity to UV light at the given wavelength. 8. The composition of claim 7, wherein the disodium salt is disodium 2,2- (1,5-penta-3-yl-1,4-dienyl) bis (5-azidobenzenesulfonate); 2,6-di (p-azidobenzal) -cyclohexanone; 2,6-di (p-azidobenzal) -4-methyl-cyclohexanone; 2,5, bis- (sodium 4-azido-2-sulfobenzal) cyclopentanone; And 4,4'-diazid benzalacetone-2,2-disulfonic acid disodium salt. 8. The coating of claim 7, wherein the photosensitive disodium salt is in the range of 1-30% by weight of the solution. ※ Note: It is disclosed by the contents of the first application.