CN1137165A

CN1137165A - Cathode ray tube, internal magnetic shield and method of manufacturing same

Info

Publication number: CN1137165A
Application number: CN96101477A
Authority: CN
Inventors: 末広勉
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 1995-02-15
Filing date: 1996-02-15
Publication date: 1996-12-04
Anticipated expiration: 2016-02-15
Also published as: KR960032569A; JPH08222142A; CN1135596C; JP3312518B2; MY120412A

Abstract

A plate is cut and folded to form an IMS so that internal magnetic shield sections and internal electronic shield sections are not overlapped in the front direction. Projections are formed on a plate- like hood on the long side for preventing the adjacent IMSs from being closely stuck together when they are loaded.

Description

Cathode ray tube, inner magnetic shielding and manufacture method thereof

The present invention relates to the cathode ray tube (CRT) of color television set etc., particularly relate to and be used for inner magnetic shielding and the manufacture method thereof that CRT and interior electron beam shield blade are provided with integratedly.

A color CRT inside is provided with inner magnetic shielding (IMS) and the interior electron beam shield blade (IBS) that is used for shielding earth magnetism, interior electron beam shield blade be used for shielding this CRT effective screen outside useless electron beam or be used for preventing that useless electron beam from beating reflexes to effective screen on shadow mask frame again.

Common CRT comprises the CRT of the IMS that has respectively configuration and IBS and has also CRT as the IMS of IBS.

Yet its shortcoming is that to have respectively the cost of CRT of the IMS of configuration and IBS very high.

Another shortcoming be have also as the working (machining) efficiency of the complex manufacturing technology of the CRT of the IMS of IBS and making low.

The lamination efficient that to also have a shortcoming be IMS is low.

An object of the present invention is to provide the inner magnetic shielding that a kind of improved cost is low and lamination efficient is high.

Another object of the present invention provides a kind of improved cathode ray tube that uses this inner magnetic shielding.

A further object of the present invention provides a kind of method of making inner magnetic shielding of improved high effect.

For realizing above-mentioned purpose, the present inventor finds when using the inner magnetic screen device that constitutes with basic the 1st and the 2nd symmetrical shield blade of the center line of length direction, the characteristic of this IMS will be identical with original IMS or better, and this original inner magnetic screen device comprises the 3rd and the 4th shield blade that the 1st and the 2nd shield blade is added and the center line of Width is symmetrical substantially.

In addition, constitute the inner magnetic screen device, can weld, technology such as riveted joint and only need shear and bend single sheet of material and just form this inner magnetic screen device and interior electron beam screening arrangement, therefore might realize lower cost and improve working (machining) efficiency by this method.

Further, form inner magnetic screen device and interior electron beam screening arrangement and do not make it upwards overlapping forwardly, can improve a yard folded efficient.

According to the cathode ray tube of the 1st scheme of the present invention comprise the panel glass bulb, the infundibulate shell that connects along the sidewall of this panel glass bulb and the inner magnetic shielding that is positioned at the infundibulate shell; This inner magnetic shielding have with a pair of long shield blade of the trunnion axis of the effective screen on panel glass bulb symmetry location and with the panel glass bulb on a pair of short shield blade of vertical axis positioned parallel of effective screen; Wherein this forms on monolithic the method for short shield blade by the bending sheet metal long shield blade and this.In addition, according to cathode ray tube of the present invention comprise the panel glass bulb, the infundibulate shell that connects along the sidewall of this panel glass bulb and the inner magnetic shielding that is positioned at the infundibulate shell; This inner magnetic shielding comprises inner magnetic screen device and interior electron beam screening arrangement, the inner magnetic screen device has the 1st and the 2nd shield blade with the basic symmetry of the center line that is parallel to length direction location, be used for influence of magnetic field in the shielded cathode ray tube, interior electron beam screening arrangement is perpendicular to the 1st and the 2nd shield blade and symmetrical substantially with the center line that is parallel to Width, and electron beam screening arrangement is used for shielding the useless electron beam of effective screen outside in this; Wherein form inner magnetic screen device and interior electron beam screening arrangement by partial cut and crooked single sheet of material.

Further, in inner magnetic shielding of the present invention, the inner magnetic screen device preferably also has with the basic symmetry of the center line that is parallel to Width the 3rd and the 4th shield blade location and that engage with the 1st and the 2nd shield blade.Can improve the characteristic of IMS by the further structure of the 3rd and the 4th shield blade of this method.

According to inner magnetic shielding of the present invention the bonding part is arranged preferably so that when the folded a plurality of inner magnetic shielding of sign indicating number, be used for a space is provided between adjacent inner magnetic shielding, and in making the electron beam screening arrangement along the place ahead to not with inner magnetic screen device overlaid.

Constitute this bonding part by this method and just can avoid that adjacent inner magnetic shielding is adjacent to mutually when the folded a plurality of inner magnetic shielding of sign indicating number, help taking out inner magnetic shielding.

In inner magnetic shielding of the present invention, the 1st and the 2nd shield blade of interior electron beam screening arrangement is preferably formed as towards the front end of electron gun side bending.

In inner magnetic shielding of the present invention, interior electron beam screening arrangement has been preferably formed as two curved front ends.

Come two curved these front ends just can prevent effectively that electron beam in the cathode ray tube from getting on the inner magnetic screen sheet and penetrate towards aperture grille according to the method.Constitute the bonding part by this method and just can avoid that adjacent inner magnetic shielding is adjacent to mutually when sign indicating number is folded a plurality of inner magnetic shielding, and help moving of inner magnetic shielding.

Method according to the making inner magnetic shielding of the 3rd scheme of the present invention may further comprise the steps: the preparation single sheet of material; The 1st time the partial cut sheet material forms the inner magnetic screen device; Electron beam screening arrangement in the 2nd time the partial cut sheet material forms; The 1st time bent sheet forms the inner magnetic screen device; And the 2nd bent sheet forms interior electron beam screening arrangement.

To make these and other purpose and characteristics of the present invention clearer by following description with reference to the preferred embodiment that accompanying drawing carried out.

Brief Description Of Drawings

Fig. 1 is the outward appearance perspective view of the original IMS (function that does not have IBS) of one roll forming;

Fig. 2 is the outward appearance perspective view of the original IMS (function that does not have IBS) that is made of two shield blade;

Fig. 3 A is the outward appearance perspective view of the original IMS (function that does not have IBS) that is made of four shield blade;

Fig. 3 B is the outward appearance perspective view of the original IMS (function that does not have IBS) that is made of four shield blade;

Fig. 4 is the outward appearance perspective view of the original IMS (function with IBS) that is made of two shield blade;

Fig. 5 is the one procedure of making the method for IMS shown in Figure 4;

Fig. 6 is the outward appearance perspective view of the original IMS (function with IBS) that is made of six shield blade;

Fig. 7 is the outward appearance perspective view according to the IMS of the 1st embodiment of the present invention;

Fig. 8 is to use the perspective view of the CRT that is opened of IMS shown in Figure 7;

Fig. 9 is the one procedure of making the method for IMS shown in Figure 7;

Figure 10 A is the drawing in side sectional elevation of IMS along the X-X line of Fig. 7;

Figure 10 B is the drawing in side sectional elevation of IMS along the X-X line of Fig. 7;

Figure 10 C is the drawing in side sectional elevation of IMS along the X-X line of Fig. 7;

Figure 11 is the profile of the state during for the folded a plurality of IMS shown in Figure 7 of description code;

Figure 12 is the outward appearance perspective view according to the IMS of the 2nd embodiment of the present invention; And

Figure 13 is the miscontacting of screen flow characteristic that is illustrated in according to causing owing to earth magnetism among the IMS of the present invention.

Before the explanation preferred embodiment, at first illustrate in greater detail prior art, with for referencial use with reference to accompanying drawing.

Fig. 1, Fig. 2, Fig. 3 A and Fig. 3 B are that expression is used for original C RT and itself does not have the outward appearance perspective view of the IMS of IBS function.

IMS1 shown in Figure 1 has the shape that one is rolled into, and IMS2 shown in Figure 2 is formed by connecting by two shield blade 2a and 2b, and this two shield blade all is the individual sheets material to be bent through shearing form, and links together at connecting portion 15 places with technologies such as welding or riveted joints.IMS3 shown in Fig. 3 A and Fig. 3 B is formed by connecting by A sheet 4a and 4b and B sheet 5a and 5b, and this A sheet and B sheet shearing foil material are as shown in Figure 3A made, and then, shown in Fig. 3 B, couple together at connecting portion 6 places by technologies such as welding or riveted joints.

Fig. 4 and Fig. 6 are used for the outward appearance perspective view that original C RT also has the IMS of IBS function.

IMS7 shown in Figure 4 is formed by connecting by 7a and 7b two parts, and these two parts are as shown in Figure 5 fine sheet to be sheared to bend to form, and then, couple together at connecting portion 9 places by welding or riveting process.

IMS7 has the IBS8 that is integrally formed therewith.

IMS11 shown in Figure 6 is A sheet 12a, 12b, B sheet 13a, and 13b and

IBS part

14a, 14b links together with technologies such as welding or riveted joints and makes.

Yet, use Fig. 1, Fig. 2, the IMS1 shown in Fig. 3 A and Fig. 3 B, 2 and 3 CRT require IBS is provided separately, and this just has the high shortcoming of cost.

In addition, IMS7 shown in Figure 4, still must link together 7a and 7b two parts in manufacturing process, thereby working (machining) efficiency is low so can make cost lower owing to have IBS part 8.

IMS shown in IMS11 shown in Figure 6 or the non-careful Japanese publication JP6-124661 is because will be by A sheet 12a, 12b, B sheet 13a, and 13b and

IBS part

14a, 14b three parts are welded, thus complex manufacturing technology, the cost height.In addition, the shortcoming of IMS11 is in order to transport etc. and during the folded a plurality of IMS of sign indicating number,

IBS part

14a, 14b can meet B sheet 13a, 13b, and therefore, adjacent IMS sign indicating number mutually folds very tightly, to pile up efficient low thereby make.

Below preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The 1st embodiment

Fig. 7 is the outward appearance perspective view according to the IMS20 of present embodiment.

As shown in Figure 7, IMS20 has inner

magnetic screen sheet

21a and 21b, interior electron

beam shield blade

22a and 22b, installation portion 23, main body 25 and the long edge tongue 26 that corresponds respectively to the 1st shield blade and the 2nd shield blade.Groove 24 is formed on the main body 25, and tab 27 is formed on the long edge tongue 26.

As shown in Figure 8, IMS20 is arranged in the CRT, is between infundibulate shell 30 and the aperture grille 10, and is fixed on the aperture grille 10.This aperture grille 10 is fixed on the panel glass bulb 31.

As shown in Figure 9, IMS20 washes out mid portion 40 with Sheet Metal Forming Technology from single sheet of material, and punching is got off, and the part that stays is sheared to bend and become a monolithic again, like this, does not just need technologies such as welding or riveted joint in manufacturing process.Simultaneously, this just can make IMS20 with many forcing press processing single sheet sheet materials along assembling line, perhaps processes with the separate unit forcing press that can carry out the multistep punching operation, for example carries out 5 punching production from fine sheet and goes out IMS20.

Inner

magnetic screen sheet

21a and 21b bend fine sheet shown in Figure 9 to form with shearings such as Sheet Metal Forming Technologies, this two shield blade is located relatively symmetrically with the center line of length direction, and have bending 21a1 at its two ends on one side, inner

magnetic screen sheet

21a and 21b are used for shielding earth magnetism.

Interior electron

beam shield blade

22a and 22b shear fine sheet shown in Figure 9 to bend to form, this two shield blade is with the symmetrical location of the center line of Width, and its effect is the useless electron beam beyond effective screen of shielding CRT or prevents that useless electron beam from beating and reflexing on effective screen on the shadow mask frame again.

Electron

beam shield blade

22a and 22b in settling so just can make it to make progress forwardly not and inner magnetic screen sheet 21a that comprises bending 21a1 and 21b overlaid.

Making such positioning relation between inner

magnetic screen sheet

21a and 21b and interior electron beam shield blade 22a and the 22b, just can be when the folded a plurality of IMS20 of sign indicating number, make inner

magnetic screen sheet

21a and 21b and can be close to mutually in abutting connection with the interior electron beam shield blade 22a and the 22b of inner magnetic screen sheet.

Correspondingly, can avoid among the IMS11 shown in the image pattern 6 like that

IMS part

14a and 14b to collide with this IMS20 and make a yard folded decrease in efficiency with B sheet 13a and 13b.

Figure 10 A, 10B and 10C have provided the part sectioned view of IMS20 along the X-X line of Fig. 7.

Shown in Figure 10 A, electron beam shield blade 22a is bent towards direction (direction of the arrow A) location back to inner

magnetic screen sheet

21a and 21b shown in Figure 7 with respect to main body 25, shield blade 22b is similar to shield blade 22a.Shown in Figure 10 B, shield blade 22a also can be with respect to direction (direction of arrow B) the location bending of main body 25 towards inner

magnetic screen sheet

21a and 21b, perhaps shown in Figure 10 C, also can bend in the direction of arrow A, be bent to form the bending of two places in the direction of arrow B at its leading section again at main body 25 places.Two curved in such a way its leading sections just can prevent effectively that the electron beam in the cathode ray tube from getting on the interior electron beam shield blade and penetrate towards aperture grille.

Shearing bends fine sheet shown in Figure 9 and forms installation portion 23, and location bending shown in Figure 10 A, and this installation portion 23 is fixed on the mounting portion 126 of aperture grille.

Shearing bends fine sheet shown in Figure 9 and forms long edge tongue 26, and this long edge tongue 26 is located relatively symmetrically with the center line of length direction, and preposition is provided with tab 27.

Method with punching press forms this tab 27, and its effect is when sign indicating number is folded a plurality of IMS20, prevents that another IMS is close on the whole surface of IMS20, thereby helps taking out IMS20.

Four jiaos of punching press main body 25 and form four grooves 24, its effect is to increase intensity, projection also can be set replace groove 24.

As mentioned above, IMS20 shears with impact style and bends individual sheets and make.Therefore, manufacture craft is simple, thereby can reduce cost of manufacture.

In addition, because IMS20 has interior electron

beam shield blade

22a and 22b, this just can be used as IBS and IMS integratedly.Therefore, IMS20 is used for CRT, just need not connects an IBS separately.Because no longer need to make the equipment of IBS etc., so just can reduce the cost of manufacture of CRT.

From prototype, IMS20 has the performance that is better than original IMS.

Figure 13 shows the location drawing of effective screen characteristic of a CRT of comparison, and use is compared according to the CRT of the IMS20 of present embodiment and the characteristic of the CRT that uses original IMS.

Specifically, roughly the same by the miscontacting of screen amount that the earth magnetic field causes at A point shown in Figure 13 (Y end), the pp value (m) of the bias among the IMS20 is " 48 ", is " 47 " among the IMS originally.

On the other hand, at B point (on the angle) shown in Figure 13, just improved much with IMS20 by the miscontacting of screen amount that the earth magnetic field causes, the pp value (m) of the bias among the IMS20 is " 39 ", and is " 67 " among the original IMS.

In addition, can reach the high folded efficient of sign indicating number with IMS20, and after sign indicating number is folded, take out easily.

The 2nd embodiment

Figure 12 is the outward appearance perspective view according to the IMS30 of present embodiment.

As shown in figure 12, the bending 21a1 that

B sheet

31a and 31b is connected to inner magnetic screen sheet 21a on the IMS20 shown in Figure 12 and 21b with welding or technology such as riveted joint goes up and constitutes

IMS30.B sheet

31a and 31b are processed in the place ahead of IMS30 upwards not and interior electron beam shield blade 22a and the equitant shape of 22b.

For example, if IMS30 is used for large-sized CRT, and effectively the influence of screen useless electron beam in addition is bigger in this CRT, and IMS30 can suppress this influence effectively.

Claims

1. cathode ray tube comprises:

A panel glass bulb;

An infundibulate shell that connects along the sidewall of said panel glass bulb; And

An inner magnetic shielding that is positioned in the said infundibulate shell, this inner magnetic shielding have the short shield blade of the vertical axis positioned parallel of symmetrical long shield blade of locating of a pair of trunnion axis with the effective screen on the said panel glass bulb and the effective screen on a pair of and said panel glass bulb;

Said a pair of long shield blade and a pair of short shield blade are formed a slice by the mode of bending sheet metal.

2. cathode ray tube comprises:

A panel glass bulb;

An inner magnetic shielding, said inner magnetic shielding comprises inner magnetic screen device and interior electron beam screening arrangement, said inner magnetic screen device has the 1st and the 2nd shield blade with the basic symmetry of the center line parallel with length direction, be used for the influence in the magnetic field in the shielded cathode ray tube, interior electron beam screening arrangement is perpendicular to the said the 1st and the 2nd shield blade, and locate substantially symmetrically with the center line that is parallel to Width, said electron beam screening arrangement is used for shielding the useless electron beam of effective screen outside;

Wherein said inner magnetic screen device and interior electron beam screening arrangement form by partial cut and bending single sheet of material.

3. according to the inner magnetic shielding of claim 2, it is characterized in that said inner magnetic screen device also has with the center line that is parallel to Width to locate substantially symmetrically, and the 3rd and the 4th shield blade that engages with the 1st and the 2nd shield blade.

4. according to the inner magnetic shielding of claim 2, it is characterized in that also comprising the bonding part, so that when the folded a plurality of inner magnetic shielding of sign indicating number, be used between adjacent inner magnetic shielding, providing the space, and electron beam screening arrangement location in making, make its along the place ahead to not with inner magnetic screen device overlaid.

5. according to the inner magnetic shielding of claim 2, it is characterized in that the said the 1st and the 2nd shield blade is formed with towards the front end of electron gun side bending.

6. according to the inner magnetic shielding of claim 2, it is characterized in that said interior electron beam screening arrangement is formed with two curved front ends.

7. method of making inner magnetic shielding, said inner magnetic shielding comprises inner magnetic screen device and interior electron beam screening arrangement, said inner magnetic screen device has the 1st and the 2nd shield blade with the basic symmetry of the center line parallel with length direction location, be used for the influence in the magnetic field in the shielded cathode ray tube, interior electron beam screening arrangement is perpendicular to the said the 1st and the 2nd shield blade, and locate substantially symmetrically with the center line that is parallel to Width, said electron beam screening arrangement is used for shielding the useless electron beam of effective screen outside; Said method comprises the steps:

The preparation single sheet of material;

The 1st time the partial cut sheet material forms said inner magnetic screen device;

The 2nd time the partial cut sheet material forms said interior electron beam screening arrangement;

The 1st time bending sheet materials forms said inner magnetic screen device; And

The 2nd time bending sheet materials forms said interior electron beam screening arrangement;

Form said inner magnetic shielding therefrom with formed inner magnetic screen device and formed interior electron beam screening arrangement.