WO1996021237A1

WO1996021237A1 - Film-type deflection yoke and its production

Info

Publication number: WO1996021237A1
Application number: PCT/KR1995/000180
Authority: WO
Inventors: Baek Young Choi; Soo Ryong Byun
Original assignee: Orion Electric Co., Ltd.
Priority date: 1994-12-29
Filing date: 1995-12-28
Publication date: 1996-07-11
Also published as: AU4317096A; KR960026047A; AR001335A1

Abstract

Disclosed are film-type deflection members (LF and RF) in a color picture tube, which comprises a plurality of films each containing at least an electrical conductive line patterned so as to produce magnetic field in a given pattern. The electrical conductive lines are insulated with one another forming conductive layers, and the conductive layers are superimposed with an insulation layer between adjacent layers. The production of the conductive line pattern is realized by etching of copper layers. The hardened deflection members (LF and RF) are fixed on bobbin (135). This bobbin serves as supporting member and is mounted at the neck of the tube. On the perimeter of the bobbin (135) there are arranged the magnetic cores (36 and 37).

Description

Film-type deflection yoke and its production

FILM-TYPE DEFLECTION MEMBER, DEFLECTION YOKE EMPLOYING IT AND A METHOD FOR FABRICATING SUCH DEFLECTION YOKE

TECHNICAL BACKGROUND

The present invention concerns the deflection yoke of a color picture tube and a method for fabricating it. The deflection yoke is to deflect the electron beams emitted from the electron gun system of a color picture tube.

Referring to Fig. 1, a color picture tube 10 generally comprises a panel 12 having a panel surface 18, a phosphor screen 20 formed on the back of the panel surface 18, a neck 14 containing an electron gun structure 11 for producing electron beams 19a, 19b directed towards the phosphor screen 20, a funnel 13 for connecting the neck 14 and the panel 12, and a deflection yoke 17. The funnel 13 has an internal conductive layer (not shown) contacting a positive electrode 15. A shadow mask 16 with a plurality of slots 16a is placed directly behind the screen 20. The deflection yoke 17 includes a horizontal deflection coil structure for producing horizontal deflection magnetic field to horizontally deflect the electrom beams 19a, 19b and a vertical deflection coil structure for producing vertical deflection magnetic field to vertically deflect the electron beams 19a, 19b. The deflection magnetic fields are properly varied to scan the phosphor screen 22 thus providing two dimensional images through the panel 12.

Conventionally, the horizontal deflection coil is formed in a saddle type, and the vertical deflection coil in a toroidal type. A deflection yoke 17 comprises a pair of toroidal vertical deflection coils 31, 32 and a pair of saddle horizontal deflection coils 33, 34 as shown in Figs. 2 and 3. The pair of saddle horizontal deflection coils 33 and 34 are oppositely arranged on the upper and the lower part of the inside wall of a bobbin 35, and the pair of vertical deflection coils 31 and 32 wound oppositely around a core structure 36, 37 in a toroidal type. Although not shown, the vertical deflection coils may be arranged on the outer surface of the bobbin 31 in a saddle type, and in this case, the core structure 36, 37 is mounted on the vertical deflection coils.

The core structure consists of an upper and a lower core 36 and 37, which facilitates the winding of the coils around the core structure. Namely, after winding separately the vertical deflection coils 31 and 32 around the upper and the lower cores 36 and 37, they are assembled together. In the saddle horizontal deflection coils 33 and 34, the left coil part 33b, 34b and the right coil part 33a, 34a should be wound to make currents flow in opposite directions. The upper and the lower saddle deflection coil 33 and 34 are arranged on both sides of a pair of projections 35a and 35b of the bobbin 35. As shown in Fig. 4, the left and the right coil part 33a and 33b of the upper saddle horizontal deflection coil 33 are designed to make the currents flow in the opposite directions, and likewise the left and the right coil part 34a and 34b in the opposite directions, so that assembling the pair of saddle horizontal deflection coils 33 and 34 causes the left coil part 33a, 34a and the right coil part 33b, 34b to flow the currents in the opposite directions.

The saddle horizontal deflection coil 33 has a side winding part 33a, 33b for producing the horizontal deflection magnetic field 33, a front and a rear winding part 33c and 33d forming the end turns, and a front and a rear opening portion 33f and 33e for securing proper convergence characteristics and faciliating the fabrication, as shown in Fig. 4.

Fig. 5 is a cross sectional view taken along line 5-5 of Fig. 4, which shows the number of the winding turns in fine angle intervals dθl, dΘ2 according to the angles Θl and Θ2 with reference to the horizontal axis X. In order to satisfy the convergence characteristics, the distribution of the coil density is very complicated together with considering the opening portions 33e, 33f, and therefore it is virtually impossible to wind the coils to rapidly vary the coil density by using a conventional winding method. Hence, the optimum convergence characteristics may not be secured. Moreover, as described with reference to Fig. 4, it is impossible to completely eliminate the magnetic field influence due to the end turn front and rear winding parts 33c and 33d, thereby degrading the convergence characteristics and the color purity.

Referring to Fig. 6 for illustrating a coil shaping structure for winding coils into the saddle horizontal deflection coil 33. The coils are wound in a cavity 43 created between male and female arbors 41 and 42. The coils are delivered in the direction indicated by arrow B in the drawing with rotating the male and female arbors. The cavity 43 is made partially narrow so as to vary the coil density according to the angles Θl, Θ2 of the saddle horizontal deflection coil 33. A pin 44 is projected in the direction indicated by arrow c just before the positions of the opening portions 33e, 33f so as to prevent the opening portions 33e, 33f from being wound.

However, because the winding length becomes different according to the circular angle and the axial direction, it is difficult to obtain a given coil density only by using the coil shaping structure rotating at a given speed. Hence, the uniformity of the coil winding is not secured resulting in the degradation of the convergence. Further, the winding shape varies according to the temperature, and the slippage of the conductive lines makes the characteristics of the product non-uniform.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a deflection yoke employing a film-type deflection member and a method of fabricating it.

According to the present invention,there is provided a film-type deflection member used in a color picture tube, which comprises a plurality of films each containing at least an electrical conductive line patterned so as to produce magnetic field in a given pattern. The electrical conductive lines are insulated with one another forming conductive layers, and the conductive layers are superimposed with an insulation layer between adjacent layers. Electrical connection members are provided for connecting the conductive lines to produce the magnetic field of a given pattern. Preferably, the conductive lines of the film-type deflection members are formed in layers exposed at both ends in step, and the electrical connection members have a plurality of conductive lines deposited like step with an insulating layer between them, and the conductive lines of said conductive lines have respectively a pair of connection members exposed to be connected with the electrical connection parts of the film-type deflection members.

One of the film-type deflection members consists of a flexible printed circuit (FPC) having a patterned conductive lines insulated from one another . The insulating layers between the conductive lines are formed of adhesive material, and the upper and the lower insulating materials are such as polyimid, polyester, etc. A connection protective layer of insulating material is formed over the uppermost and the lowermost of the deflection members. At least one of the horizontal and the vertical deflection coils comprises a plurality of film- type layers each having electrical conductive lines electrically connected with one another.

A supporting member is provided in the bobbin to reinforce the film-type deflection members so as to maintain a given form. The supporting member is integrated with the bobbin, and the film-type deflection member is supported inserted in said supporting member. The connection members are saddle type to electrically connect the film-type deflection members. The connection members are formed in toroidal type electrically connecting the film-type deflection members. The deflection yoke comprises a film-type deflection member having at least a film containing conductive lines arranged in a given pattern to produce magnetic field, and connection members for electrically connecting the conductive lines so as to produce magentic field. The conductive lines of the film- type deflection members are formed like step exposed at both ends, the connection members are deposited like step with an insulating between them, and opposite connection parts are provided exposed in the ends of the connection members to connect with said deflection members. The film- type deflection members consist of a plurality of flexible printed circuit films with a patterned conductive lines superimposed together.

According to another embodiment of the present invention, there is provided a method for fabricating the deflection yoke of a color picture tube including a horizontal deflection coil arranged around the neck-funnel connection for horizontally deflecting the electron beams, a vertical deflection coil arranged perpendicularly to said horizontal deflection coil for vertically deflecting the elctron beams, a bobbin for mounting said deflection coils around said neck-funnel connection, and cores arranged on the perimeter of said bobbin, which comprises the steps of:

forming the pair of film-type deflection members in a given pattern;

electrically connecting the film-type deflection members by means of connectors so as to produce magnetic field; and

fixing the film-type deflection members on said bobbin.

The film-type deflection members are preferably hardened in a given form to attach to said bobbin by means of heating and cooling in the forming step. The fixing step includes the step of fixing the central part of the connectors on the peripheral surface of the cores. The step of froming the film-type deflection members is to deposit a plurality of flexible films like step, and form connection parts by exposing both ends of the conductive lines of the flexible films. The connection is performed by depositing said films like step with insulating layers interposed between them and exposing both ends to form opposite connection parts. According to another embodiment of the present invention, there is provided a method for fabricating the deflection yoke of a color picture tube, which comprises the steps of:

forming in a film-type at least one of the horizontal and the vertical deflection coils by repeating the process of depositing a copper layer on an insulating layer, forming a plurality of conductive lines by etching the copper layer, and depositing an insulating layer on the conductive lines;

electrically connecting the film-type deflection members by connectors in the form of coils; and

fixing the film-type deflection members on the bobbin.

The present invention will now be described with reference to the drawings attached only by way of example.

BRIEF DESCRIPTION OF THE ATTACHED DRAWINGS

Fig. 1 is a partially cross sectioned view for schematically illustrating the structure of a color picture tube; Fig. 2 is a cross sectional view taken along line 2-2 of Fig. 1 for illustrating a pair of conventional saddle horizontal deflection coils and a pair of vertical deflection coils;

Fig. 3 is a cross sectional view taken along line 3-3 of Fig. 2;

Fig. 4 is a perspective view for illustrating the saddle horizontal deflection coils as shown in Figs. 2 and 3;

Fig. 5 is a cross sectional view taken along line 5-5 of Fig. 4 for illustrating the distribution of the saddle horizontal deflection coil;

Fig. 6 is a cross sectional view for schematically illustrating the coil shaping structure for fabricating the horizontal deflections coil of the Fig. 4;

Fig. 7 is a plane view for schematically illustrating a film used for constituting a multi-layer film-type deflection member according to an embodiment of the present invention;

Fig. 8 is a longitudinal cross sectional view for illustrating the electrical connections between a plurality of parts constituting a multi-layer film-type deflection member according to another embodiment of the present invention;

Fig. 9 is a partial enlarged cross sectional view for illustrating the structure of the conductive line layers of the multi-layer film-type deflection member shown in Fig. 8;

Fig. 10 is a schematic diagram for illustrating the electrical connections of the inventive multi-layer film- type deflection member;

Fig. 11 is a schematic perspective view for illustrating the inventive film-type deflection yoke;

Fig. 12 is a view similar to Fig. 2 for illustrating the cross sectional view of the film-type deflection yoke Of Fig. 11;

Fig. 13 is a cross sectional view taken along line 13-13 similar to Fig. 3;

Fig. 14 is a plane view for illustrating a film-type deflection yoke according to another embodiment of the present invention; Fig. 15 is a flow chart for illustrating the steps of fabricating a film-type deflection yoke according to the present invention;

Fig. 16 is a partial cross sectional view for illustrating a forming structure for forming the inventive film-type deflection member into a given form; and

Fig. 17 is a plane view for illustrating the test result of spotting the electron beams on the screen of a color picture tube with the inventive film-type deflection member.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Fig. 7, there is shown a flexible printed circuit (FPC) film 50 for fabricating a film-type deflection member, which includes electrically conductive lines arranged in a given pattern insulated from one another. A plurality of conductive layers fl,...,fn are laid as shown in Fig. 8, where there is shown the structure for externally connecting the conductive lines 51, 52 of the film 50 by means of connecting members 57, 58.

A pair of conductive lines 51 and 52 are symetrically arranged in the conductive line part 50c between the end external connection parts 50a and 50b with reference to the axis X-X. However, the conductive lines may be arranged in any pattern in a plane. An insulating adhesive material is filled between the pair of conductive lines 51 and 52. The conductive line layers fl,...,fn each consisting of a pair of conductive lines 51 and 52 are superimposed together with insulating layers Pl,...,Pn between them, as shown in Fig. 8.

The insulating layers P2,...,Pn have both ends cut off to form the electrical connection parts 50a, 50b, ....

There are electrical connection members 57a, 57b, 58a,

58b, ... respectively connected with the electrical connection parts 51a, 51b, 52a, 52b, .. It is preferable to make the ends have a step-like form in order to simultaneously attach the connection members 57, 58, ... in the multi-layer construction. In addition, connection part protective layers 55 are preferably formed by an insulating adhesive material hardened on the uppermost and the lowermost of the connection parts in order to secure the electrical connection of the electrical connection parts 51a, 51b, 52a, 52b, ...

Referring to Fig. 9, a plurality of conductive lines

E are arranged on an insulating layer PI such as polyimid, polyester, etc., in a given pattern so as to form a conductive line layer fl. The plurality of conductive lines are insulated from one another by means of insulating adhesive materials Ad. In this way, there are formed alternately and repeatedly a given number of insulating layers P2,...,Pn and a given number of conductive line layer F2,...,fn. Finally, an upper insulating protective layer Po of polyester is laid as the uppermost coverlay. Although a plurality of conductive line layers are described with reference to Figs. 8 and 9 to be superimposed with insulating from one another by means of an insulating layer, it is possible to superimpose a plurality of films 50 each having a conductive line layer between the upper and the lower insulating layers, as shown in Fig. 7.

Referring to Fig. 10, a pair of film-type deflection members LF and RF are respectively composed of a plurality of films LF1, ...,LFn and RF1, ... ,RFn. Describing the electrical connections of the films, a conductive line 51 of the uppermost film LF1 of a film- ype deflection member

LF has at one end an electrical connection part 51b connected externally with a connection member Ao, and at the other end an electrical connection part 51a connected to an electrical connection part 62a at one end of a conductive line 62 of the uppermost film RF1 of another film-type deflection member RF by means of a connection member Al. The electrical connection part 62b at the other end of the conductive line 62 is connected to the electrical connection part 52b at one end of the other conductive line 52 of the uppermost film LF1 by means of a connection member Bl. The other electrical connection part 52a of the other conductive line 52 is connected through a connection member Cl to an electrical connection part 61a at one end of the other conductive line 61 of the uppermost film RF1, while the other electrical connection part 61b is connected through a connection member Dl to an electrical connection part of a conductive line of the second film LF2 of the film-type deflection member LF. The other electrical connection part of the conductive line is connected through a connection member A2 to a conductive line of the second film RF2 of the film-type deflection member RF. Thus, a plurality of connection members Al, ... ,An;Cl, ... ,Cn;Bl, ... ,Bn;Dl, ... ,Dn are used to connect the conductive lines of one of the film-type deflection members with those of the other so as to produce the magnetic field.

As shown in Fig. 10, the connection members Al, ... ,An,-Cl, ... ,Cn are used to connect the conductive lines of same layers so that each of the films has two of the connection members. However, the connection members Dl,...,Dn-l are to connect the conductive lines of different layers, so that the connection members Bl...Bn;Dl...Dn-1 at the right side of Fig. 10 should be separated. The connection members and connection parts may have any kind of form. For example, the ends of the coils may have a connection pin.

Following is the description of the specific construction of the inventive film-type deflection yoke with reference to Figs. 12 and 13.

Referring to Fig. 13, the connection member C may connect the film-type deflection members LF and RF along the direction indicated by arrow T to obtain a toroidal type connection, or along the direction indicated by arrow S to obtain a saddle type connection. It is preferable to attach the connection member C on the outer surface of the cores 36 and 37. Hence, the inventive film-type deflection yoke 117 has no end turn. Supporting members 135a and 135b may be integrally formed with or detachably attached to the bobbin 135 as shown in Fig. 12 so as to make the film- type deflection members LF and RF maintain a given form. If the film-type deflection members LF and RF are hardened to maintain a given form, it is possible to directly attach them to the bobbin 135.

According to another embodiment of the present invention as shown in Fig. 14, there are shown a pair of film-type deflection member FL and FR, which are connected in the same way as the conventional saddle horizontal deflection coils. In this case, the regions FL and FR separated by the lines are provided with conductive lines arranged in a given pattern.

Referring to Fig. 15, an inventive method for fabricating the film-type deflection members using a flexible printed circuit film (FPC) comprises the following steps:

In step SI, a module is designed to form a conductive line pattern of each of the film layers constituting the film-type deflection members according to the convergence characteristics, etc.

In step S2, a mask film is prepared to conform with the conductive line structure of the film layers.

In step S3, the films for the deflection members are obtained according to the process for fabricating a conventional printed circuit film. The films are laid together to produce the film-type deflection member F.

As shown in Fig. 9, deposited on an insulating layer Pi made of a material such as polyimid, polyester, etc., is a cleaned conductive metal thin film, on which a photoresist is deposited to etch the metal film to produce a conductive pattern arranged on conductive layers fl,...,fn. Then, an insulating adhesive layer Ad is laid over it. Again laid over it is an insulating layer P2 of polyimid, polyester, etc. In this way, there is obtained a multi-layer film-type deflection member F. The upper protective layer Po is preferably made with a greater thickness and strength than the other insulating layer P2.

Thereafter, the film-type deflection member F made according to the process of Fig. 15 is formed by using a forming structure 60 as shown in Fig. 16 in step S5. Otherwise, the insulating layers Pi, ... ,Pn and the metal film are formed according to the pattern of the portion of the bobbin 135 for attaching the deflection members, and etched. As shown in Fig. 16, the film-type deflection member F is put on a forming punch 62 as shown by two- dotted chain line in the drawing, and the corresponding forming die 61 is pressed towards the forming punch to shape the film-type deflection member F. Then, the heating lines heat the deflection member, and harden it by cooling to maintain the shape. Otherwise, a current is applied to the film-type deflection member F to heat. In this case, it is preferable to perform the connecting step S6 before the forming step S5 in Fig. 15. Instead, it is possible to maintain a given shape by means of a supporting structure 31a formed separately from the bobbin 135 with omitting the forming step S5.

As shown in Figs. 8 and 10, the connecting member C is connected to the hardened deflection member F in step S6, fixed to the bobbin 135 in step S7. The convergence characterisics of the inventive film-type deflection yoke are compared with the conventional yoke in three spots SPl, and SP2, SP3 on the screen as shown in Fig. 17. In this test, a color picture tube of 14", 0.28p is used with eliminating the ferrite sheet. The result of the test is as follows:

Table 1 The Inventive Deflection Yoke

Screen\Sample No.l No.2 No.3 No.4 No.5 deviation position

SPl 0.05 0.08 0.02 0.07 0.06 0.02

SP2 -0.09 -0.1 -0.12 -0.07 -0.05 0.024

SP3 0.03 0.04 0.05 0.01 0.07 0.02

Table 2 The Conventional Deflection Yoke

Screen\Sample No.l No.2 No.3 No.4 No.5 Deviation position

SPl -0.02 -0.13 0.1 -0.17 -0.02 0.11

SP2 -0.45 -0.20 -0.57 -0.10 -0.28 0.17 SP3 0.15 0.05 0.10 0.23 0.15 0.06

* in the tables, "+" or "-" indicates the red electron beam positioned left or right with reference to the blue electron beam in case of SPl and SP3, and the blue electron beam positioned upper or lower with reference to the red electron beam in case of SP2.

As shown in the above tables, the standard deviation of the inventive yoke is closer to zero than the conventional yoke, the convergence characteristics of the inventive yoke are considerably improved compared to the conventional yoke. Moreover, the end turns are not necessary, thus improving the color purity.

Claims

WHAT IS CLAIMED IS:

1. A film-type deflection member used in a color picture tube comprising a plurality of films each containing at least an electrical conductive line patterned so as to produce magnetic field in a given pattern.

2. A film-type deflection member as defined in Claim 1, wherein the electrical conductive lines are insulated with one another forming conductive layers, and the conductive layers are superimposed with an insulation layer between adjacent layers.

3. A film-type deflection member as defined in Claim l, including at least an electrical connection member for connecting the conductive lines to produce the magnetic field of a given pattern.

4. A film-type deflection member as defined in Claim 3, wherein the conductive lines of said film-type deflection members are formed in layers exposed at both ends in step, and said electrical connection members have a plurality of conductive lines deposited like step with an insulating layer between them, and the conductive lines of said conductive lines have respectively a pair of connection members exposed to be connected with the electrical connection parts of said film-type deflection members.

5. A film-type deflection member as defined in Claim

1, wherein one of said film-type deflection members consists of a flexible printed circuit (FPC) having a patterned conductive lines insulated from one another .

6. A film-type deflection member as defined in Claim

2, wherein the insulating layers between the conductive lines are formed of adhesive material, and the upper and^' the lower insulating materials are one of polyimid and polyester.

7. A film-type deflection member as defined in Claim

3, wherein a connection protective layer of insulating material is formed over the uppermost and the lowermost of said deflection members.

8. In a deflection yoke of a color picture tube including a pair of horizontal deflection coils oppositely arranged in the neck-funnel connection for horizontally deflecting the electron beams emitted from the electron gun system, a pair of vertical deflection coils oppositely arranged perpendicularly with said horizontal deflection coils for vertically deflecting the electron beams emitted from the electron gun system, at least one of said horizontal and said vertical deflection coils comprising a plurality of film-type layers each having electrical conductive lines electrically connected with one another.

9. A deflection yoke as defined in Claim 8, wherein a supporting member is provided in the bobbin to reinforce said film-type deflection members so as to maintain a given form.

10. A deflection yoke as defined in Claim 9, wherein said supporting member is integrated with said bobbin, and said film-type deflection member is supported inserted in said supporting member.

11. A deflection yoke as defined in Claim 8, wherein said connection members are saddle type to electrically connect said film-type deflection members.

12. A deflection yoke as defined in Claim 8, wherein said connection members are formed in toroidal type electrically connecting the film-type deflection members.

13. In a color picture tube including an evacuated bulb, an electron gun system mounted in the neck of said bulb for emitting electron beams, and a deflection yoke arranged on the outer surface of the connection part of the neck and the funnel for deflecting said electron beams, said deflection yoke comprising a film-type deflection member having at least a film containing conductive lines arranged in a given pattern to produce magnetic field, and connection members for electrically connecting said conductive lines so as to produce magentic field.

14. A color picture tube as defined in Claim 13, wherein the conductive lines of said film-type deflection members are formed like step exposed at both ends, said connection members are deposited like step with an insulating between them, and opposite connection parts are provided exposed in the ends of said connection members to connect with said deflection members.

15. A color picture tube as defined in Claim 13, wherein said film-type deflection members consist of a plurality of flexible printed circuit films with a patterned conductive lines superimposed together.

16. A method for fabricating the deflection yoke of a color picture tube including a horizontal deflection coil arranged around the neck-funnel connection for horizontally deflecting the electron beams, a vertical deflection coil arranged perpendicularly to said horizontal deflection coil for vertically deflecting the elctron beams, a bobbin for mounting said deflection coils around said neck-funnel connection, and cores arranged on the perimeter of said bobbin, comprising the steps of:

forming said pair of film-type deflection members in a given pattern;

electrically connecting said film- ype deflection members by means of connectors so as to produce magnetic field; and

fixing said film-type deflection members on said bobbin.

17. A method as defined in Claim 17, wherein said film-type deflection members are hardened in a given form to attach to said bobbin by means of heating and cooling in said forming step.

18. A method as defined in Claim 16, wherein said fixing step includes the step of fixing the central part of the connectors on the peripheral surface of the cores.

19. A method as defined in Claim 16, wherein the step of froming said film-type deflection members is to deposit a plurality of • flexible films like step, and form connection parts by exposing both ends of the conductive lines of said flexible films, the connection being performed by depositing said films like step with insulating layers interposed between them and exposing both ends to form opposite connection parts.

20. A method for fabricating the deflection yoke of a color picture tube including a horizontal deflection coil arranged around the neck-funnel connection for horizontally deflecting the electron beams, a vertical deflection coil arranged perpendicularly to said horizontal deflection coil for vertically deflecting the elctron beams, a bobbin for mounting said deflection coils around said neck-funnel connection, and cores arranged on the perimeter of said bobbin, comprising the steps of:

forming in a film-type at least one of the horizontal and the vertical deflection coils by repeating the process of depositing a copper layer on an insulating layer, forming a plurality of conductive lines by etching said copper layer, and depositing an insulating layer on said conductive lines;

electrically connecting said film-type deflection members by connectors in the form of coils; and

fixing said film-type deflection members on the bobbin.