CN1284696A - Frame assembly of colour CRT - Google Patents

Abstract

A frame body for a color cathode-ray tube includes a plurality of main frames with fixed intervals, a plurality of subframes supporting the two ends of each main frame, wherein each main frame is installed with one recess along the length direction of at least one side. The bracket is fixed between the main frames and subframes, thereby, the microphonic effect of the frame modules can be improved, because it reduce the chromatic purity of the color cathode-ray tube to advance the natural frequency of the frame modules.

Description

The frame assembly of color cathode ray tube

The present invention relates to a kind of color cathode ray tube, more particularly, is a kind of frame assembly that supports shadow mask in color cathode ray tube.

It is the tension force that is used for supporting the thin shadow masks generation of selecting cathode-ray tube (CRT) electron beam color that frame assembly is set, and it is by avoiding this tension adjustment to the both sides of the shadow mask that is welded in this causing that by external impact or sound wave shadow mask is produced to be vibrated.This frame assembly also supports this shadow mask keeping a required space between shadow mask and fluorescent film, thereby can allow that electron beam separately accurately clashes into relevant pixel.To explain that below the said frame assembly is used for an example on the flat color cathode ray tube of prior art, it has eliminated the video screen bending radius fully, thereby has avoided image to produce distortion and make effective visual angle reach maximization.Fig. 1 represents the cut-away section of the flat color cathode ray tube of prior art.

With reference to figure 1, the planar coloured cathode ray tube of prior art is provided with one and is positioned at its front portion, it is the flat panel 1 that image shows side, scribble the fluorescent film 4 of three kinds of colors of red, green, blue within it on the surface, one has the shadow mask 3 of the function of electron beam 6 colors of selecting the directive fluorescent film, one is welded to the cone 2 on the surface plate rear surface, it makes its inner vacuum shape that keeps, one contracts to cone tubular neck portions 10 dorsad, one electron gun (not shown) and that is used for divergent bundle at neck is looped around the deflection coil 5 that outer surface of cone is used for deflection beam.In addition to these, also have by the fixing frame assembly 7 of the pin on the flat panel inner surface 16 and reed 8 and be fixed on the inner screening 9 of frame assembly rear end, be used to shield the influence that electron beam that earth magnetism is deflected coil deflection with protection exempts from the external magnetic field.In above-mentioned cathode-ray tube (CRT), electron gun ejected electron bundle 6 can pass shadow mask 3 in upper and lower, left and right direction deflection, strikes at last on the video screen 15, makes fluorescent surface luminous with reproduced image.

Simultaneously, with reference to figure 2 and 3C, the step of the inner structure of brief description assembling cathode-ray tube (CRT).

The step of assembling cathode ray tube interior structure comprises compression frame assembly 7 so that shadow mask 3 has a rate of curving that designs, shadow mask 3 is fixed on the frame assembly so that pretension is acted on the shadow mask, is that the reed 8 that will be installed on the frame assembly is fixed on the pin that is installed on the panel 1 at last.Also have one and make G/R (electron beam packet rate; Three electron beams 6 are distributed in the pattern on the fluorescent film) reach optimized process, wherein G/R is expressed as follows according to the equation (1) of the fluoroscopic resolution that is fixed with various parameter expressions: $G/R=\frac{3\×S\×Q}{\mathrm{Ph}\×L}----------\left(1\right)$

Here, S represents the component of deflection coil, and Q represents the distance of shadow mask to panel inner surface, and Ph represents the distance between the groove center, and L represents the center of electron beam of deflection coil deflection and the distance between the panel inner surface.That is to say that shown in Fig. 1 and 3B, G/R need be 1, is exactly the resolution of video screen the best.Yet, in the prior art, be that 1 optimized electronic bundle packet rate can not be met.In other words, shown in Fig. 3 B, have defective on the structure of the cathode-ray tube (CRT) of prior art, promptly shadow mask to the distance " Q " of panel inner surface less than or greater than designed distance, the R that needs bump fluorescent film 4 relevant pixels like this, G, the G/R of B electron beam just in time is not G/R=1 just, still, perhaps with G/R＜1 grouping, perhaps go group (de-grouped), therefore, just reduced colour purity with G/R＞1.The reduction of colour purity is the problem that exists by in following prior art structure and the assembly, and promptly the displacement of groove causes on the shadow mask 3.A main cause of groove displacement is to strike the heat energy that the electron beam on the shadow mask 3 converts to and make shadow mask 3 produce thermal expansions by about 80%, second thermal expansion that frame assembly 7 is produced by shadow mask 3, will produce vault phenomenon (doming) like this, also reduce colour purity.The Another reason of groove displacement is vibration or the collision that the cathode-ray tube (CRT) outside causes, passes to frame assembly 7 by panel 1 and pin 16.That is to say that shadow mask 3 is passed in this vibration of frame assembly 7 so that video screen produces vibration (seeing the dotted line of Fig. 3 A), i.e. microphony (howling).

Meanwhile, because cathode-ray tube (CRT) flattens, it is big so that panel curves inwardly that the bending radius of panel becomes, and becomes bigger with regard to the bending radius that makes shadow mask so recently.In case the bending radius of shadow mask becomes bigger, shadow mask is flattened, to compare with the shadow mask of rapid bending, the structural strength of shadow mask will weaken many, can produce very serious microphony (howling) and vault phenomenon (doming) like this.In order to overcome this limitation, shown in Figure 4 and 5, design a kind of have tension force is offered the frame assembly 17 of shadow mask or 27 cathode-ray tube (CRT).That is to say, the step of making this frame assembly method comprises makes main frame 17a and 27a respectively, the step of sub-frame 17b and 27b, the two ends of sub-frame 17b and 27b are welded on main frame 17a and the 27a end to form the step of a rectangular frame, by on the main frame 17a that uses an independent gas booster compressor to be placed in the step of Y direction compression main frame 17a and 27a with shadow mask 3 as shown in Figure 4 compress and the 27a and remove the step of compressive load.In the case, when compressive load was removed, the shadow mask 3 that is welded on the upper surface of two symmetrical main frames was stretched at the elastic force of a certain direction (Y-direction) by main frame 17a and 27a and sub-frame 17b and 27b.Yet as shown in Figure 4, because sub-frame 17a is solid, frame assembly 7 has just increased general assembly (TW) comparatively speaking, because natural frequency and weight are inversely proportional to, so so just reduced natural frequency.That is to say, there is the problem that image rocks fast in the cathode-ray tube (CRT) of prior art, because the reduction of the natural frequency of frame assembly, not only frame assembly is very responsive to the external vibration of frequency, and the shadow mask that is supported on the frame assembly is also passed in this vibration.

Simultaneously, in order to improve frame assembly as shown in Figure 4, though a kind of frame assembly that has the groove sub-frame as shown in Figure 5 is provided.But also there is following problem in this frame assembly.Following table 1 is represented the comparison between the frame assembly shown in Figure 4 and shown in Figure 5.

	The frame assembly of Fig. 4 (17)	The frame assembly of Fig. 5 (27)
			Natural frequency for the first time	????100％	????124％
The moment of inertia of main frame	????100％	????85％
			The moment of inertia of sub-frame	????100％	????204％
The weight of frame assembly	????100％	????57％

That is to say that as shown in table 1, in order to improve natural frequency for the first time, the frame assembly of Fig. 5 just must change the section of main frame and sub-frame and change the moment of inertia of the welding method of two frameworks with weight reduction and increase sub-frame.Yet on the contrary, the moment of inertia of main frame is reduced, and will have a more weak moment of torsion, has so just hindered the reduction of microphony (howling).

Therefore, the present invention designs a kind of frame assembly of color cathode ray tube, and it can solve basically owing to be subjected to the restriction of prior art and the problem that unfavorable factor is produced.

An object of the present invention is to provide a kind of frame assembly of color cathode ray tube, it can reduce microphony.

Further feature of the present invention and effect will propose in the following description, and part will become clear in from then on describing, and perhaps can learn by putting into practice the present invention.Purpose of the present invention and other effect will be by being familiar with in the structure that written instructions and claims and accompanying drawing particularly point out and obtaining.

In order to realize according to purpose of the present invention, these and other effect, as summarizing and summarizing described, the frame assembly of color cathode ray tube comprises the main frame of a plurality of fixed intervals, the sub-frame at each main frame two ends of a plurality of supports, wherein each main frame is provided with a groove along its length in the one side at least.

Following inequality will satisfy.

N * C 〉=2/3 * A, ' A ' represents the length of main frame here, ' n ' represents the quantity of each main frame groove, the length of ' C ' expression groove.

Following inequality also will satisfy.

10 * C1≤A, C1 represents the distance between the groove here.

This frame assembly comprises that also the joint reinforcement is to connect the parts between main frame and the sub-frame.

Following inequality will satisfy.

F1≤B1, F2≤A1, F3≤B2, F1 represents to engage the height of reinforcement here, and F2 represents its width, and F3 represents its thickness, the height in B1 vice framework cross section, B2 represents its thickness, and A1 represents the width in main frame cross section, and A2 represents its thickness.

The detailed description that should be understood that the summary of front and back is to be used for for example and to explain, its objective is to claims of the present invention provides further explanation.

Included accompanying drawing is used to provide to further understanding of the present invention, and they are added in the instructions and form the part of instructions, and illustrated embodiment of the present invention is used to explain principle of work of the present invention together with its description:

Among the figure:

Fig. 1 represents to have in the prior art side view of the Flat CRTs of partly analysing and observe;

Fig. 2 representational framework assembly is fixed in the cut-open view of this panel;

Fig. 3 A represents the work diagrammatic sketch of color cathode ray tube;

Fig. 3 B represents to have the R of corresponding electron beam grouping resolution, G, the distribution plan of B fluorescent film;

Fig. 3 C represents the distance between the shadow mask hole;

Fig. 4 represents the skeleton view of prior art frame assembly first embodiment;

Fig. 5 represents the skeleton view of prior art frame assembly second embodiment;

Fig. 6 A represents the front-side perspective view of the frame assembly of most preferred embodiment according to the present invention;

Fig. 6 B represents the backside perspective view of the frame assembly of most preferred embodiment according to the present invention;

Fig. 7 A represents along the cut-open view of I among Fig. 6-I line;

Fig. 7 B represents along the cut-open view of II among Fig. 6-II line;

Fig. 8 A-C represents the plane/front end/rear end diagrammatic sketch of third angle flange of the frame assembly of the most preferred embodiment according to the present invention.

Now, will describe in detail most preferred embodiment of the present invention with reference to the legend shown in the figure 6A-8C.To represent with identical label with parts identical in the prior art, at length not explain.The present invention proposes by the rigidity (particularly in the length side direction) of reinforced frame assembly and strengthens moment of torsion with the microphony that reduces color cathode ray tube the natural frequency of frame assembly to be improved, and its ultimate principle is as follows.

Relation between rigidity and the natural frequency is expressed as follows with equation (2): $\mathrm{\&omega;}=\frac{K}{\mathrm{\&rho;}}\&Proportional;\frac{\mathrm{<figure-callout\; id="1"\; label="E"\; filenames="0012904500091.png,0012904500092.png"\; state="\{\{state\}\}">E</figure-callout>}1}{{\mathrm{\&rho;}1}^4}----------\left(2\right)$

Here, ' ω ' represents natural frequency, the rigidity of ' K ' representational framework assembly, and ' ρ ' represents density (framework quality), and ' E ' represents elastic modulus, and ' I ' represents moment of inertia, ' 1 ' representational framework length.From equation (2) as can be known: in case the rigidity of frame assembly ' K ' is reinforced, natural frequency ' ω ' will become big.That is to say that for the frame assembly that the same material with equal length and same elastic modulus is formed, as long as moment of inertia, anti-deformation has strengthened, rigidity has also strengthened, and natural frequency will be improved.Because it can be defined as: ω ∝ I, preferably the rigidity with frame assembly strengthens so that the natural frequency of frame assembly is improved.According to above-mentioned principle, shown in Fig. 6 A-8, provide a kind of rectangular frame work assemblies with a pair of main frame 107a and a pair of sub-frame 107b.This main frame 107a has the groove 108 that a pair of mutual spacing is C1, and each groove 108 has height C2 and length C in its outside.Trapezoidal sub-frame 107b has height ' D ' and width ' W ' with raising moment of inertia and rigidity.Be provided with support, the reinforcement of link, each support have height ' F1 ', width ' F2 ', and thickness ' F3 ' is used to connect main frame 107a and sub-frame 107b.Groove 108 has reduced the vibration displacement that produced by frame vibration, and wherein (2 * C) greater than 2/3rds o'clock of main frame length ' A ', just can provide the most effective moment of inertia for the total length of two of each main frame 107 grooves.The rigidity that is main frame 107a is enhanced so that first natural frequency increases, and the proper vibration of main frame will be present in outside the external vibration frequency range to avoid two phase mutual interference between the frequency like this.In other words, the reduction of the frequency of the microphony that produces owing to the natural frequency of main frame 107a and the phase mutual interference between the foreign frequency can improve the microphony of cathode-ray tube (CRT).On the contrary, if the total length of two grooves 108 of each main frame 107a is less than three of main frame length/two o'clock, because the effect that does not have vibration displacement to reduce just must limit the relation between groove length and the main frame length as above.Distance C 1 between the groove 108 is designed to can be to reduce natural frequency greater than 10% greater than 1/10th of main frame length ' A '.Preferably make between the groove 108 distance C 1 greater than main frame length ' A ' 1/10th to keep stiffening effect.And because support 109, the reinforcement of link has structurally been strengthened small and weak moment of torsion, and it increases natural frequency, and the frequency that produces microphony also can be lowered.Yet, because the increase of weight has just reduced natural frequency, rather than be used to add strong vibration greater than the support 109 of certain dimension limit.In a word, be designed to respectively equal, or less than the width A1 of main frame 107a, the width ' F2 ' of the support 109 of the height B 1 of sub-frame 107b and the thickness A 2 of main frame or sub-frame or B2, highly ' F1 ', and thickness ' F3 ' has improved natural frequency very effectively.

Meanwhile, following table 2 expression is by using the result of limited element analysis technique to structure analysis that frame assembly is done, from then on as can be known, compare with the frame assembly of prior art among Fig. 4, the moment of inertia of main frame and sub-frame has been improved 159% and 145% respectively, natural frequency has improved 73%, and weight has reduced 23% simultaneously.

Table 2

	The frame assembly of Fig. 4 (17)	The frame assembly of Fig. 5 (27)	The frame assembly of Fig. 6 of the present invention
				Natural frequency for the first time	????100％	????124％	????173％
The moment of inertia of main frame	????100％	????85％	????259％
				The moment of inertia of sub-frame	????100％	????204％	????245％
The weight of frame assembly	????100％	????57％	????77％

Specificity analysis according to the microphony of top form shows that the moment of torsion of frame assembly has damaged the performance of microphony.Therefore, in the present invention, not only moment of inertia is enhanced having strengthened the rigidity of main frame, and the moment of torsion of frame assembly also is enhanced, thereby has improved the performance of microphony.

As mentioned above, the frame assembly of color cathode ray tube of the present invention has following effect.

Frame assembly in the color cathode ray tube of the present invention can improve the microphony of frame assembly, this effect is the reason that makes color cathode ray tube colour purity variation, by at main frame groove being set, the intrinsic frequency of frame assembly is improved along with the enhancing of the rigidity of main frame, by between the assembly of main frame and sub-frame, setting up support, improved the moment of inertia of frame assembly.

Those skilled in the art can make various modifications and variations and not break away from spirit of the present invention and protection domain the frame assembly of color cathode ray tube of the present invention obviously. Therefore, the intent of the present invention is that it has covered its various modifications and variations, as long as these modifications and variations drop in claim and the equivalent scope thereof.

Claims (5)

1. the frame assembly of a color cathode ray tube comprises:

The main frame of a plurality of fixed intervals;

The sub-frame at each main frame two ends of a plurality of supports;

Wherein each main frame is provided with a groove along its length in the one side at least.

2. frame assembly as claimed in claim 1, wherein: satisfy following inequality,

N * C 〉=2/3 * A, ' A ' represents the length of main frame here, ' n ' represents the quantity of each main frame groove, the length of ' C ' expression groove.

3. frame assembly as claimed in claim 1, wherein: also to satisfy following inequality,

10 * C1≤A, C1 represents the distance between the groove here.

4. frame assembly as claimed in claim 1, wherein: this frame assembly also comprises the reinforcement of link, in order to connect the parts between main frame and the sub-frame.

5. frame assembly as claimed in claim 4, wherein: satisfy following inequality,

F1≤B1，F2≤A1，F3≤B2，

Here F1 represents the height of the reinforcement of link, and F2 represents width, and F3 represents thickness, the height in B1 vice framework cross section, and B2 represents thickness, and A1 represents the width in main frame cross section, and A2 represents thickness.

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