CN1061466C - Cathode-ray tube with glare reducing, neutral density faceplate coating and process - Google Patents

Abstract

A cathode ray tube includes a front screen having an external surface with a coating of neutral density to reduce glare. The coating comprises a material of lithium silicate type, at least two materials for attenuating light, and an operative quantity of an abrasion-resistant material, as a separate component, or in combination with a light attenuating material. The light attenuating materials are selected from the group consisting of a mixture of carbon black, a black ink, a blue ink, a black colorant and a blue colorant. A method of applying said coating is also described.

Description

Low dazzle Braun Tude And Its Preparation Method with intermediate density faceplate coating

The present invention relates to a kind of cathode ray tube (CRT), scribble the coating of the medium density that can reduce dazzle on the outer surface of its panel, particularly, the present invention relates to the prescription of this coating.

On the outer surface of crt panel, be coated with coating, can low cost substitute the dark glass panel effectively, to strengthen the contrast of the shown image of picture tube with intermediate density.

The low glare properties that the intermediate density faceplate coating is had is known in the art, and is described by for example 3,898, No. 509 United States Patent (USP)s of the people such as Brown of announcement on August 5th, 1975.Mention in this patent, a kind of China ink (india ink) spraying plating on the outer surface of crt panel, so that the whole emission measure of panel is reduced to 42% from 69% (during no coating), has been reduced dazzle from face.This China ink contains the carbon and the poly-lithium silicate (lithium polysilicate) of about 4% (percentage by weight).The effect that its emission light reduces is the function of optical attenuation quantity of material in the coating ingredients.

Term used herein " reduction dazzle " is meant the brightness of reflection video and the reducing of definition of environment light source.Dazzle from environment light source hinders people to visual watching on the picture tube panel, therefore the beholder is caused adverse effect.

The people's such as Deal that on February 24th, 1976 announced 3,940, No. 511 United States Patent (USP) proposes to use a kind of coating, its constituent class is similar to above-mentioned United States Patent (USP) 3, the coating that proposes for 898, No. 509, difference is that it comprises a kind of colouring agent of proofreading and correct color, repay in the coating undesirable tone in addition, or increase the desired tone that has in the coating from carbon particle.

The coating of some intermediate densities that above-mentioned patent for reference is mentioned, each all has such shortcoming, be all to contain the machinery that can reduce coating and the pigment of chemical integrity in the coating, that is the wear resistence of coating reduced, thereby be subjected to the infringement of surrounding environment easily.

The problem that desire of the present invention solves is the coating of a kind of intermediate density of preparation, only contain very a spot of organic additive and adhesive in the used coating solution of this coating, use the material that abrasion resistance is arranged simultaneously, be subjected to the possibility of surrounding environment infringement with the minimizing coating, and help obtaining required reflectance spectrum scope.

Cathode ray tube of the present invention has a panel, scribble the coating that contains poly-lithium silicate of the intermediate density that can reduce dazzle on its outer surface, this coating also comprises at least two kinds of optical attenuation materials, and this optical attenuation material is selected from following one group of material: carbon black slurry, tusche, Lan Mo, black colouring agent and cyan coloring agent; And a kind of colloidal silica of its amount of may command is as anti-friction material, and this material both can be used as independent composition, also can be used as a part of component of optical attenuation material.

The invention allows for a kind of method that on the panel outer surface of cathode ray tube, applies the intermediate density coating that can reduce dazzle, may further comprise the steps:

A) clear up described outer surface (39);

B) NH of usefulness 2-8% ₄F ₂The above-mentioned surperficial 10-80 of H solution corrosion second;

C) above-mentioned surface is heated to the temperature of 30-80 ℃ of scope;

D) the intermediate density coating (37) that will contain a kind of reduced dazzle of the colloidal silica as anti-friction material is coated on the described surface;

E) make described coating drying;

F) the described surface heating that will have described coating is up to about 100 ℃ temperature, and being incubated one section is enough to make the completely crued time of described coating;

G) be that the 50-60 ℃ of water in the scope cleans the about 15-60 of described coating second with the temperature; With

H) make described coating drying.

The present invention will be described in more detail below in conjunction with accompanying drawing.

Fig. 1 is the partial longitudinal section that comprises CRT of the present invention;

Fig. 2 is the enlarged drawing of a picture tube panel part of analysing and observe along Figure 12-2 line;

Fig. 3 is a curve chart, illustrates as the quilt percentage of the spectral reflectivity of long function, and this sets of curves is made panel and other plates that contain the trendy coating of different component amount that some contain no coating control board;

Fig. 4 a, 4b and 4c are a suite line chart, and the spectral reflectance as the angle of reflection function is shown, and three figure are that 440nm, 550nm and 600nm make at wavelength respectively.

Cathode ray tube 21 shown in Figure 1 comprises a glass shell of finding time, and this shell has a neck 23, connects together with funnel part 25.Face glass 27 is connected on the funnel part 25 by dense glass seal section 29.The luminescent screen 31 that contains fluorescent material is attached on the inner surface of panel 27.Forming sediment on the luminescent screen 31 to know has light reflective metals (for example aluminium) film 33, as shown in Figure 2.Luminescent screen 31 quilts can be seen this image from producing luminous image behind the electron beam scanning of electron gun 35 by panel 27.On the outer surface 39 of panel 27, scribble the coating 37 of the intermediate density of the novelty that can reduce dazzle, when watching, can improve the contrast of image by panel.

The coating 37 of the intermediate density of low dazzle is similar to 4 of the Deal that announces October 23 nineteen ninety, 965, No. 096 described low dazzle coating of United States Patent (USP), but its difference is in the colloidal silica (colloidal silica) that contains controllable amounts in this new coating, compare with the prior art that does not contain the colloidal silica coating, improved wear resistence.

Available any known cleaning method carries out carefully please managing to the outer surface 39 of the panel 27 of the sealing picture tube 21 that vacuumizes, removing fouls such as dust, fiber, grease, scum silica frost, and notes not scratching panel surface.The most handy commercial complexing agent clean surface of cleaning, water flushing again.Use two ammonium hydrogen difluorides (ammonium bifluoride) the solution wiping of 2-8% weight ratio to use soft water more then with corrosion surface, i.e. washed with de-ionized water, and make its drying with air curtain (aircurtain), in case the water mark occurs.Panel is placed in the stove or subsequently and heats to about 30-80 ℃ in other suitable modes, and with the anti-friction material of poly-lithium silicate, controllable amounts (can be used as in the coating independent component or as with a part of component of optical attenuation material) and the aqueous solution of at least two kinds of optical attenuation materials apply.Wherein two kinds of optical attenuation materials are by selecting in following one group of material: carbon black slurry, tusche, Lan Mo, black colouring agent and cyan coloring agent.Poly-lithium silicate is the stable Ludox of a kind of lithium (lithium-stabilizedsilica sol), wherein SiO ₂With Li ₂The ratio of O is between about 4: 1 to 25: 1.This colloidal sol is substantially free of other anions except that hydroxyl (hydroxyl).The lithium stabilized colloidal silica is that with the different substantially of lithium metasilicate solution the latter is the compound that dissolves in solvent, and is not colloidal sol.In the heating process afterwards, the Ludox coating drying that lithium is stable forms a kind of lithium silicate coating.One deck or which floor this coating can make with the technology (as using spray method) of any routine.This coating is at air drying, and heating is elevated to above 15-60 ℃ of ambient temperature (about 22 ℃) its temperature then.Then clean about 15-60 second with warm water (temperature is 50-60 ℃).In air, make the coating drying carefully, avoid on coating, being stained with Soft flocks or other extraneous dust.

Above-mentioned coating has the usefulness that reduces dazzle, can compare with the coating that does not contain anti-friction material so that reflection light diffusing simultaneously, has improved visual contrast, and its wear resistence also is improved.

Example 1

With any known cleaning method the outer surface 39 of the panel 27 of a CRT21 who has vacuumized is cleared up, to remove dirts such as dust, grease, scum silica frost.Do corrosion slightly with the difluoro hydrogen ammonium salt solution of 5% weight ratio then, again with washed with de-ionized water.Subsequently, to the panel heating of this picture tube, the liquid coating compound with a kind of novelty is ejected on the hot glass again in 30-80 ℃ of scope.This coating compound is made by coloring mixture, carbon slurry and water are mixed.Wherein coloring mixture is 29 grams (10.6% weight ratio), contain polysilicate (poly-lithium silicate) 48 and black colouring agent, its commodity label is " CDIDispersions ", by N.J. Niu Huake city (Newark, N.J.) produce, as CDI BS 15188 ", comprise by Wei Mingdun city, U.S. Delaware state (Wilmington, DE) polysilicates 48 of 28.4 grams (10.4% weight ratio) made of E.I.DuPont company and the black colouring agent of 0.6 gram (0.2% weight ratio); The carbon slurry is 15 grams (5.5% weight ratio); Water is 228.5 grams (83.9% weight ratio).

The carbon slurry of using in the above-mentioned coating formula comprises:

The surfactant of 0.3% percentage by weight, for example Brij 35 SP of Wei Mingdun city, U.S.'s Delaware state ICI U.S. state company product;

The dispersant of 1.2% weight ratio, for example Land of Steady Habits Greenwich city (Greenwich, CT) the Marasperse CBA-1 or the CBOS-3 of Ligno technology company product;

The substrate solution of 1.5% weight ratio (base solution) for example contains weight ratio and is 30% Ammonia;

The carbon of 4.4% weight ratio, for example Massachusetts, United States Wa Ershan city (Waltham, MA) BP-1300 of Cabot company product;

The cabosil of 7.5% weight ratio (Colloidal silica), the Ludox that produces of Wei Mingdun city, U.S.'s Delaware state E.I.DuPont company for example, AM is to increase abrasion resistance; With

Remainder is soft water (being deionized water).

Coating is at air drying, and heating makes it further curing then.If, then glass surface is heated to, and be incubated 2-4 minute above the above 15-60 of ambient temperature ℃ with infrared heating element (as the Calrod heater).But if with stove heating glass surface, then picture tube will be placed in the stove 15-30 minute, perhaps reaches till 85 ℃ to furnace temperature, cleans the about 15-60 of picture tube second with warm soft water (50-60 ℃) then, makes its drying again.

Example 2

Second kind of coating compound is by getting up to make with following mixing of materials:

The polysilicate 48 of 29 grams (10% weight ratio) and the mixture of black colouring agent, its commodity label is CDI BS15188, described in example 1;

24.5 the carbon slurry as prescription in the example 1 of gram (9% weight ratio); With

The water of 219 grams (80.4% weight ratio).

This coating applies in the mode described in the example 1 and is dry, thereby has coated a kind of DARD of being called 70 GLOSS coatings at panel outer surface.

Example 3

The third coating compound is by getting up to make with following mixing of materials:

The BS15188 of CDI as described in Example 1 of 29 grams (10.6% weight ratio);

39.5 the above-mentioned carbon slurry of gram (14.5% weight ratio); With

The water of 204 grams (74.9% weight ratio).

This coating applies in the mode described in the example 1 and is dry, thereby a kind of DARK of being called 70 GLOSS HC (high contrast) coatings are provided.

Example 4

A kind of control coating does not contain dark pigment, but contains anti-dazzle (STDAG70GLOSS) coating of standard, and this control coating is by getting up to make with following mixing of materials:

28.4 the polysilicate 48 by Wei Mingdun city, U.S. Delaware state E.I.DuPont register of company of gram (10.4% weight ratio); With

244.1 the water of gram (89.6% weight ratio).

In coating of the present invention, the concentration of poly-lithium silicate 48 can change in the 1-20% weight percentage ranges, but is preferably in 8.86-10.5% weight ratio scope; And the concentration of black wash can change in the 1-30% weight percentage ranges, but is preferably in 5.5-14.5% weight ratio scope.Except can the black colouring agent of 0.1-0.4% weight ratio range, also can in this compound, adding the cyan coloring agent of about 0.03% weight ratio, to eliminate the brownish tone that causes owing to carbon.Cyan coloring agent can select methylenum careuleum (methylene blue), and it can be buied from many shops.

One group of spectral reflectance rate curve of selected these new coatings shown in Fig. 3.As the reflectivity of the panel of the not coating of reference standard with curve 1 expression.The reflectivity of the anti-dazzle coating of the standard that does not conform to dark pigment that curve 2 expression is made by example 4 with by method described in above 4,965, No. 096 United States Patent (USP) incorporated by reference.Curve 3 and 4 is represented by the new prescription of above-mentioned example 3 and example 2 respectively and is only starched the reflectivity of coatings different on the content at carbon black.Curve 3 is being had stronger reflectivity by length for the about 625nm scope of 400-, and its coating contains the carbon black slurry of 14.5% weight ratio; And curve 4 has lower reflectivity at wavelength for the 400-625nm scope, and its coating contains the carbon black slurry of 9.0% weight ratio.Can find out that from these curves the carbon slurry content in the coating formula has only slight influence to the percentage of spectral reflectivity.

Example 5

Also studied a kind of prescription, this prescription is used the tusche with other China inks or colorant combination, but the carbon black described in the use-case 1-3 is not starched, and also uses the colloidal silica of controllable amounts, to increase wear resistence.

Identical with described in the example 1 of the preparation of the panel outer surface of using for coating 39 and usage.The prescription of this of coating the 5th embodiment is following material will be combined:

40.7 the polysilicate 48 of gram (12.8% weight ratio);

22.8 the high-quality tusche of gram (7.2% weight ratio), (Hunt Manufacturing, Statesville NC) produce by Statesville city, North Carolina Hunt manufactory;

3.2 the blue China ink of gram (1% weight ratio) is by PelikanAG (Pelikan AG, Hanover, Germany) product in Hanoverian, Germany city;

6.4 the colloidal silica (Ludox AM) of gram (2% weight ratio); With

The deionized water of 244 grams (all the other).

Example 6

The prescription of another variation of the basic coating compound of China ink is made of the following material of combination:

40.7 the CDI BS 15188 of gram (13.7% weight ratio), it comprises

39.9 the gram (13.4% weight ratio) polysilicate 48 and

0.8 the black colouring agent (CDI BS 15188) of gram (0.3% weight ratio);

6.0 the high-quality tusche of gram (2% weight ratio);

6.4 the colloidal silica (Ludox AM) of gram (2.1% weight ratio); With

245 gram (remaining) deionized waters.

Example 7

Following prescription is a controlled prescription of tusche, does not wherein contain colloidal silica.This prescription comprises:

40.7 the polysilicate 48 of gram (13.6% weight ratio);

11.4 the high-quality tusche of gram (3.8% weight ratio);

4.0 the blue China ink of gram (1.3% weight ratio); With

The water of 244 grams (remaining).

After the black coating drying of above-mentioned routine 5-7, make the coating insulation at about 100 ℃ glass surface heating so that it solidifies, this with example 1 in coating is incubated at the above 15-60 of ambient temperature ℃ is different.Identical with described in the example 1 of cleaning and drying steps.

Fig. 4 a, 4b and 4c contrast to the carbon black slurry coating of the black basic coating of example 5, example 1 with as the spectral reflectance situation as the angle of reflection function of the no coating panel of reference with regard to 440nm, 550nm and 600nm respectively, show direct reflection (SR) measured value with reference plane two kinds of coatings relatively.The ordinate of each figure can be arbitrary parameter, but it only shows the relative reflection case of each coating and reference plate.

The anti-dazzle of coating in example 1 and 5 and the common pigmentation of intermediate density not being contributed to some extent (for example in the example 4) coating is compared, and its result of the test is summarised in the following table." anti-dazzle (Gloss) " in the table is the surface reflectivity measured value of measuring at place, 60 ° of angles of off-normal with glossmeter.The value of 0-100 scope, the catoptrical % number of the no scattering of expression.The visible increment that " polishing " expression is found out according to surface reflectivity is promptly worked as with Al ₂O ₃Be coated on the coating panel of picture tube and with a Merlon test block with 10 gram/cm ²The power same position of wiping glass surface and the amount of the luster mottlings that produces back and forth.Move back and forth, promptly each circulation is designated as 1X at every turn.The visible wearing and tearing line of " scuffing " expression.At " polishing " duration of test, check by the mill coating surface, to determine its abrasion condition." light output " is unit with foot one youth primary/milliampere (FL/mA), the white light output when being illustrated in the equivalent colour temperature and being 6500 ° of K.The measured value that " pipe face reflectivity " expression compares the spectral reflectivity and the calibration standard of the picture tube under experimental condition with spectroradiometer." contrast ratio " is maximum luminous value and the ratio of minimum luminous value, during test, is to be under 25 foot one candle light (fc) condition." " each of white point that obtains a selection when being illustrated in colour temperature and being 6500 ° of K on a C.I.E figure specified the ratio of the relative magnitude of current of primary color component for R/B and R/G current ratio." SR " expression spectral reflectance size, it is the measured value with corner reflection meter surface reflectivity when incidence angle is 13.5 °.These value representations go out by the percentage of the incident light of direct reflection.Table

	Example 4		Example 1	Example 5
						Control AG		The carbon slurry	Tusche
Anti-dazzle (GLOSS)	51		49	49
					Polishing	40X		10X	1X
Scratch	＞60X		＞30X	5X
					Light output * (FL/mA)	29.1		22.9	24.3
Pipe face reflectivity	.118		.080	.090
					Contrast ratio * (25fC)	8.2		9.3	8.9
R/B current ratio *	1.90		1.74	1.76
					R/G current ratio *	1.59		1.46	1.54
SR	1.3		1.3	1.22
					*6500°K

Although it is different can finding out the measurement parameter of each sample coatings from last table, wherein " polishing " and " scuffing " test shows example 4 coatings of the anti-dazzle of conventional no pigment deposit, and its wear resistence is the highest., have concentration and be the carbon slurry coating of example 1 of the colloidal silica of 7.5% weight ratio, the tusche coating of ratio 5 has better wear resistence, and the latter is contained the cabosil of low concentration than other coatings, contains the pigment deposit of higher concentration than 1 of example.

Claims (8)

1. a cathode ray tube has a panel, scribbles the coating that contains poly-lithium silicate of the intermediate density that can reduce dazzle on its outer surface, it is characterized in that, this coating (37) also comprises:

At least two kinds of optical attenuation materials, this optical attenuation material are selected from following one group of material: carbon black slurry, tusche, Lan Mo, black colouring agent and cyan coloring agent; And

A kind of colloidal silica of its amount of may command is as anti-friction material, and this material both can be used as independent composition, also can be used as a part of component of optical attenuation material.

2. cathode ray tube as claimed in claim 1 is characterized in that, described coating (37) comprises the poly-lithium silicate of 1-20% weight ratio, the carbon black slurry of 1-30% weight ratio, the black colouring agent of 0.1-0.4% weight ratio, and surplus is a water.

3. cathode ray tube as claimed in claim 2 is characterized in that, described coating (37) also comprises the cyan coloring agent of about 0.2-0.4% weight ratio.

4. cathode ray tube as claimed in claim 2, it is characterized in that, described carbon black slurry comprises the colloidal silica of about 7-8% weight ratio as the carbon of anti-friction material, 4-5% weight ratio, the dispersant of 1-1.5% weight ratio, the substrate solution of 1.4-1.6% weight ratio, the surfactant of 0.2-0.4% weight ratio, and surplus is a soft water.

5. carbon black slurry as claimed in claim 4 is characterized in that described substrate solution is 30% ammonium hydroxide aqueous solution.

6. cathode ray tube as claimed in claim 1, it is characterized in that, described coating (37) comprises the colloidal silica of the poly-lithium silicate of about 8-15% weight ratio, about 1-2.1% weight ratio, the tusche of 1-8% weight ratio, second kind of coloring agent of 0.2-1.5% weight ratio, this coloring agent is selected from one group of material being made up of blue China ink and black colouring agent, and surplus is a water.

One kind on the panel outer surface of cathode ray tube coating can reduce the method for intermediate density coating of dazzle, it is characterized in that may further comprise the steps:

A) clear up described outer surface (39);

B) NH of usefulness 2-8% ₄F ₂The above-mentioned surperficial 10-80 of H solution corrosion second;

C) above-mentioned surface is heated to the temperature of 30-80 ℃ of scope;

D) the intermediate density coating (37) that will contain a kind of reduced dazzle of the colloidal silica as anti-friction material is coated on the described surface;

E) make described coating drying;

F) the described surface heating that will have described coating is up to about 100 ℃ temperature, and being incubated one section is enough to make the completely crued time of described coating;

G) be that the 50-60 ℃ of water in the scope cleans the about 15-60 of described coating second with the temperature; With

H) make described coating drying.

8. method as claimed in claim 7 is characterized in that, wherein heating steps f) in being higher than ambient temperature 15-60 ℃ scope, carry out.

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