US3813574A

US3813574A - High voltage transformer device in a horizontal deflection circuit

Info

Publication number: US3813574A
Application number: US00306406A
Authority: US
Inventors: K Sato
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1971-11-18
Filing date: 1972-11-14
Publication date: 1974-05-28
Anticipated expiration: 1991-05-28
Also published as: NL167264C; DE2256006A1; DE2264451B2; CA966933A; DE2264451A1; DE2256006C3; DE2256006B2; BE791522A; FR2165886B1; FR2165886A1; DE2264451C3; GB1387647A; NL7215629A; NL167264B

Abstract

A high voltage transformer device in a horizontal deflection circuit supplying an extra high tension (EHT) to the anode of cathode-ray tube, which comprises a low-voltage coil (primary winding) and a high-voltage coil (secondary winding) including a high-voltage side winding and a low-voltage side winding, wherein the high-voltage side winding of the high-voltage coil is more closely magnetically coupled to the low-voltage coil than the magnetic coupling between the low-voltage side winding of the high-voltage coil and the low-voltage coil, thereby suppressing variations of the high voltage output, and improving the trackability of the focusing voltage when a focusing coil is additionally provided.

Description

14 1 May 28,1974

15 1 HIGH'VOLTAGE TRANSFORMER;

DEVICE IN A HORIZONTAL DEFLECTION CIRCUIT [75] Inventor: Kohei Sato, lkeda, Japan 73 Assignee z, Matsu shita. Electric 0)., 1.111.,

. Osaka, Japan 221 Filed: Nov, 14, 1972 21 Appl. No.: 306,406-

[30] Foreign Application Priority Data Nov. 18, 1971 Japan 46-92893 Nov. 27, 1971 Japan 46-95599 Dec. x, 1971 Japan.... 46-99758 Jan. 24, 1972 Japan 479273 [52] 11.8. C1. 315/29, 336/185 [51] Int. Cl. H0lj 29/70 [58] Field of Search 315/27 R, 28, 29; 321/8 C; 330/197; 323/47-50; 310/193, 194; 336/182,

3,369,166 ,2/1968 Lake ...'.."'321/8 C 3,428,853 2/1969 Akat$u.... 315/27 R 3,445,747 5/1969 Laurent: i 321/8 C" 3,500,116 3/1970 Rietveld et a1.'. 315/27 R X 3,517,253 6/1970 Dietz 315/27 R 3,546,629 12/1970 Walker, .11.. 315/29 X 3,564,386 2/1971 Leonatdm 321/8 C Primary ExaminerLela'nd A. Sebastian Assistant Examiner-P. A. Nelson Attorney, Agent, or Firm-Stevens, Davis, Miller ,& Mosher [57] ABSTRACT A high voltage transformer device in a horizontal deflection circuit Supplying an extra high tension (E to the anode of cathode-ray tube, which comprises a low-voltage coil (primary winding) andahighwoltage coil (secondary winding) including a high-voltage side winding and a low-voltage side winding, wherein the high-voltage side winding of the high-voltage coil is more closely magnetically coupled to the low-voltage coil than the magnetic coupling between. the lowvoltage side winding of the high-voltage coil and the low-voltage coil, thereby suppressing variations of the high voltage output, and improving the trackability of the focusing voltage when a focusing coil is additionally provided.

36 Claims, 17 Drawing Figures PATENTEDmza 1974 saw 101 or m PATENTEmAv za 1974 snm us HF 10 IENIEB am 28 m4 SHEET '0 HF 10 FIG.

END (HIGH-VOLTAGE COIL SIDE) SIDE) FIG LOAD CURRENT msmsunavzm $813574 Sum 05 0F 10 FIG. 8

FOCUSING VOLTAGE LOAD CURRENT FIG. 7b

FIG. Ta

PATENTEDmza 1914 3,813,574

sum 09 0F 10 Focus me VOLTAGE LOAD CURRENT PATENTEDm 28 I974 sum 1n 0F 10 FIG.

1 HIGH VOLTAGE TRANSFORMER DEVICE IN A HORIZONTAL DEFLECTION CIRCUIT This invention relates to a high voltage transformer device which is substantially free from variations in the high voltage output and shows an improved trackability.

Conventional high voltage transformers have had such a structure that the low-voltage side windings of a high-voltage coil are disposed in proximity to a low potential portion or low-voltage coil and ,the high voltage side windings of the high-voltage coil are spaced from the low-voltage coil by a sufficient insulating distance for avoiding an abrupt potential gradient between these coilsand ensuring the electrical insulation of the high voltage portion.

In such a prior art structure, therefore, the leakage fiux between the high-voltage coil and the low-voltage coil passes through the low-voltage coil and then cuts across the low voltageside windings of the'high-voltage coil adjacent to thelow-voltage coil. As a result, there is a great variation in-the voltage induced in the highvoltage coil at various points between the first end of the coil connected to groundand the second end of the coil connected to the load. More precisely, the induced voltage is higher in the high-voltage side windings adjacent to the second end and lower in the low-voltage side windings adjacent to the first end due tothe fact that the leakage flux passing through the low-voltage coil c'utsacross the low-voltage side windings of the high-voltage coil as described above. This leads to the appearance of a higher potential at the high-voltage side windings of the high-voltage coil and is therefore undesirable from the viewpoint of insulation.

Further, the mode of variations in the high voltage output relative to high-voltage load current, or high voltage regulation, is also unsatisfactory due to, for example, an undesirable increase in the stray capacity and the high voltage output is abruptly decreased with the increase in the high-voltage load current.

It is an object of the present invention to provide a novel and improved flyback transformer device which can operate with minimized variations of the high voltage output relative to variations of load current.

- Another object of the present invention is to provide a high voltage transformer device which can supply a focusing voltage of satisfactory trackability.

In accordance with one aspect of the present invention, there is provided a high voltage transformer device comprising a low-voltage coil, a core, a highvoltage coil including a high-voltage side winding and a low-voltage side winding, and a high-voltage rectifier, wherein the high-voltage side winding of said highvoltage coil is more closely magnetically coupled to said low-voltage coil than the magnetic coupling between the low-voltage side winding of said high-voltage coil and said low-voltage coil.

In accordance with another aspect of the present invention, there is provided a high voltage transformer device comprising a low-voltage coil, a core, a highvoltage coil including a high-voltage side winding and a low-voltage side winding, and a high-voltage rectifier, wherein said high-voltage coil and said low-voltage coil are disposed so that the ratio V /nH between the voltage V induced in the high-voltage side winding of said high-voltage coil and the number of turns n thereof is smaller than the ratio V /n between the voltage V former device according to the present invention;

FIGS. 3a and 3b are diagrammtic views illustrating the structural difference between the high voltage transformer device according to the present invention and a prior art device of the samekind;

FIG. 4 is a graph showing the induced voltage distribution in the high-voltage coil of the high voltage transformer device according to the present invention and the prior art high voltage transformer device;

FIG. 5 is a graph showing the relation between the high voltage output and the load current-in the high voltage transformer device according to the present invention and the prior arthigh voltage transformer de- VlCe; Y 1

FIG. 6 is a schematic sectional view showing the structure of another embodiment of the present invention;

FIGS. 7a and 7b are diagrammaticviews showing two different manners of connection of a focusing diode in the embodiment shown in FIG. 6;

FIG. 8 is a graph showing an improved trackability of focusing voltage obtained with the high voltage transformer device shown in FIG. 6 as compared with the similar characteristic obtained with a prior .art high voltage transformer device of this kind;

FIG. 9 is a schematic sectional view with parts shown by blocks, showing the structure of a further embodiment of the present invention;

FIGS. 10a and 10b are partly sectional elevations showing two different forms of a high-voltage coil portion employed in another embodiment of the present invention;

FIG. 11 is a schematic sectional view showing another coil arrangement which may be employed in lieu of the forms shown in FIGS. 10a and 10b;

FIG. 12 is a diagrammatic view showing the electrical connection in still another embodiment of the present invention;

FIG. 13 is a schematic sectional view showing the structure of the embodiment shown in FIG. 12; and

FIG. 14 is a graph showing the relation between the focusing voltage and the load current in the high voltage transformer device shown in FIG. 12.

Referring to FIG. 1 showing one basic form of a horizontal output circuit, the circuit includes a horizontal output transistor 1, a damper diode 2, a deflection yoke coil 3, capacitors 4 and 5, and a high voltage transformer device 8 connected to a picture tube 7. The high voltage transformer device 8 comprises a highvoltage rectifier diode 9 and a high voltage transformer 10 which is composed of a core 13, a low-voltage coil 11 and a high-voltage coil 12. A terminal 6 of the lowvoltage coil 11 is connected to a dc. power supply.

While FIG. 1 shows a circuit arrangement for deriving the horizontal deflection output and high voltage output from the same transistor by way of example, it will be understood that another circuit arrangement for deriving the deflection output from another transistor may be employed in place of the circuit arrangement shown in FIG. 1.

FIG. 2 shows the structure of one form of the high voltage transformer shown in FIG. 1. Referring to FIG. 2, the low-voltage coil 11 or primary coil of the high voltage transformer 10 is wound around a coil bobbin which is mounted on the leg of the core 13. The high-voltage coil 12 or secondary coil of the high voltage transformer 10 is wound around a coil bobbin 14 disposed coaxially around the coil bobbin 15. The high-voltage coil 12 consists of a plurality of

windings

12a, 12b, 12m and 12n which are connected in series. In the arrangement shown in FIG. 2, the windings near by the winding 12a are the low-voltage side windings of the high-voltage coil 12, and the windings near by the winding 12n are the high-voltage side windings of the high-voltage coil 12. The core 13 consists of a pair of portions which are joined at a joint 16. The reference numeral 17 designates the grounded or first end of the high-voltage coil 12. I 1

One of the important features of the present invention resides in the fact that the low-voltage coil 11 is disposed adjacent to the high-voltage side windings of the high-voltage coil 12 as seen in FIG. 2. This arrangement differs entirely from the arrangement employed generally in prior art high voltage transformers. In prior art high voltage transformers, the low-voltage side windings of the high-voltage coil are disposed adjacent to the low potential portion or low-voltage coil as described before.

The operating characteristic of the" high-voltage transformer device of the present invention having such a structural difference will be described with reference to FIGS. 3a and 3b. FIG. 3a is a diagrammatic view showing the structure of the high voltage transformer device according to the present invention, and FIG. 3b is a diagrammatic view showing the structure of a prior art high voltage transformer device having a coil arrangement as above described; In the prior art high voltage transformer device, a high-voltage coil 18 including a low-voltage side winding 18a and a highvoltage side winding 18n is magnetically coupled to a low-voltage coil 19 in a relation as shown in FIG. 3b. In FIGS. 3a and 3b, a main magnetic fiux 20 is shown by the dotted lines and a leakage fiux 21 is shown by the one-dot chain line. In both the high voltage transformer devices, the main magnetic flux 20 cuts completely across both the low-voltage coil and the highvoltage coil. However, the leakage flux 21 cuts across the low-voltage side windings of the high-voltage coil in the case of FIG. 3b, whereas it cuts across the highvoltage side windings of the high-voltage coil in the case of FIG. 3a, although the amount of the leakage flux 21 is very slight compared with the main magnetic flux 20. Further, in the present invention, the highvoltage coil and low-voltage coil are disposed to give the relation between the ratio of the voltage V volts induced in the high-voltage side windings of the high-voltage coil to the number of turns n thereof and the ratio of the voltage V volts induced in the low-voltage side windings of the high-voltage coil to the number of turns n thereof.

Because of the above arrangement, there is a distinct difference between the induced voltage distribution in the high-voltage coil of the high voltage transformer device according to the present invention and that in the prior art high voltage transformer device as seen in FIG. 4. The solid line in FIG. 4 represents the induced voltage distribution or a voltage obtained by plotting the amount of voltage induced in each turn of the highvoltage coil in the high voltage transformer device according to the present invention, while the dotted line represents the induced voltage distribution in the prior art high voltage transformer device. The one-dot chain line in FIG. 4 represents the mean value and such an induced voltage distribution is seenin a device such as a power transformer in which the leakage flux is negligible.

' The solid curve in FIG. 5 shows the mode of variations of the high voltage output relative to the highvoltage load current, or the high voltage regulation, in the high voltage transformer device according to the present invention, while the dotted curve shows the high voltage regulation in the prior art high voltage transformer device. It will be clearly seen from FIG. 5 that undesirable variationsof the high voltage output can be remarkably reduced in the high voltage transformer device of the present invention comparedwith the prior art high voltage transformer device.

FIG. 6 shows another embodiment of the present invention having a focusing power supply incorporated therein. Referring to FIG. 6, a focusing coil 22 is wound around a coil bobbin 23 which is mounted on the leg of a core 13 at a position where the degree of magnetic coupling between it and a low-voltage coil 11 is less than that between a high-voltage coil 12 and the lowvoltage coil 11. The focusing coil 22 may be electrically connected to the high-voltage coil 12 and to a focusing diode 24 in a manner as shown in FlG. 7a or 7b. Referring to FIG. 7a, a capacitor 25 connects the first end of the high-voltage coil 12 to ground in ac. fashion, and at the same time, acts to smooth the focusing voltage appearing across the focusing coil 22. The arrangement shown in FIG. 7b is the sameas the arrangement in which a focusing power supply is tapped from an intermediate point of the high-voltage coil 12. The trackability of the focusing voltage obtained with the high voltage transformer device shown in FIG. 6' is shown in FIG. 8 and is compared with that of a prior art high voltage transformer device-of this kind. In FIG. 8, the thick solid line, one-dot chain line and dotted line represent the trackability obtained with the arrangements shown in FIGS. and 7b and with the prior art device respectively. The hatched portion defined between thin solid lines indicates the focusing voltage range which is required for obtaining a sound picture. The term second end of the high-voltage coil is used herein to denote the end connected to the terminal at which positive high voltage pulses appear when the other or first end of the high-voltage coil is grounded. It is to be understood that the second end does not simply indicate the end remote from the end of the coil structure at which the coiling operation is started.

A few methods as described below are very effective for improving the dielectric strength of the high voltage transformer device according to the present invention, especially the dielectric strength between the highvoltage side windings of the high-voltage coil and the low-voltage coil.

According to one. of preferred'methods, a high volt age transformer as shown in FIG. 6 is housed within a casing 26 together with a high-voltage rectifier diode 9 and the interior of the casing 26 is filled with a quantity of insulating oil as shown in FIG. 9. The charging of insulating oil in the casing 26 may result in an increase in the specific inductive capacity of the space existing before the charging of the insulating oil, and the stray capacity of the high-voltage coil may be thereby increased tov cause remarkable fluctuations of the operating characteristic of the high voltage transformer device. However, it has been found that the high-voltage regulation and trackability of the focusing voltage are entirely free from any variations when the operating characteristic of the high voltage transformer device is suitably regulated in the state in which it is submerged in the insulating oil. Referringto FIG. 9, the high voltage transformer 10 and high-voltage rectifier diode 9 are. shown housed within the casing 26 whose internal space is filled with the insulating oil 29 and the high-voltage output, focusing output, and other output and input are connected to a high voltage outputterminal 27, a focusing voltage output terminal 28, and lowvoltage output and input terminals 30 respectively.

According to a second method, a stepped coil bobbin 31 as shown in FIG. 10a or a tapered coil bobbin 32 as shown in FIG. 10b is used for mounting the highvoltage coil in the form of a split winding so as to increase the insulation distance between the high-voltage side windings of the high-voltage coil and the lowvoltage coil and to reduce the stray capacity of the high-voltage coil. In the case ofa honeycomb winding, for example, the same way of thinking may be applied to provide a structure as shown in FIG. 11 in which it will be seen that the high-voltage coil 12 is carried by a coil bobbin 33 having a shape as shown. The same way of thinking may also be applied to a bank winding.

A method for more precisely controlling the trackability of the focusing voltage will be described with reference to FIG. 12 which is a diagrammatic view showing a preferred arrangement of elements in still another embodiment of the present invention and to FIG. 13 which is the schematic sectional view showing the structure of the embodiment shown in FIG. 12. Referring to FIGS. 12 and 13, a low-voltage coil 11 is divided into a main winding 34 and an auxiliary winding 35 connected in series, and the main and

auxiliary windings

34 and 35 of the low-voltage coil 11 are closely magnetically coupled to high-voltage side windings of a high-voltage coil 12 and a focusing coil 22 respectively.

This arrangement is advantageous'in that the focusing coil 22 is more easily controlled by the magnetic flux variations of the low-voltage coil 11 than when it is less closely magnetically coupled to the low-voltage coil 11 and the variations of the focusing voltage relative to variations of the high-voltage load current can be reduced. The above effect is graphically shown in FIG. 14 in which the solid line represents the variations of the focusing voltage in the case in which the lowvoltage coil is divided into the main and auxiliary windings and the dotted line represents similar variations in the case in which the low-voltage coil is not divided into such windings.

The high voltage transformer device according to the present invention provides the following advantages:

1. the high voltage transformer device produces a high voltage output which shows remarkably reduced voltage variations.

The internal impedance Zi will be taken herein to represent the variations of the high voltage output of the high voltage transformer device. This internal impedance Zi is defined by Zi (high voltage output in kilovolts when 1, O)

- (high voltage output in kilovolts when I, A milliamperes)/A megohms,

where c I, is the high-voltage load current. The value of the internal impedance Zi in the present invention is of of Zi in prior art highvoltage transformer devices is generally of the order of 3 to 3.5 megohms. It is thus apparent that the high voltage output variations can be remarkably reduced according to the present invention.

Further, according to common practice, means such as a saturable reactor is connected in series in the dc. circuit supplying the horizontal output circuit in a television receiver for controlling the dc. power supply voltage thereby stabilizing the high voltage output. However, the effective internal impedance can only be reduced to a level of the-order of 1.5 to 2.5 megohms even with such a method. In contrast, the present invention can reduce the effective internal impedance to a lower level without requiring such a control circuit, and when such a circuit is combined with the device, the effective internal impedance can be reduced to a further lower level of the order of 0.7 to 1.7 megohms.

A so-called fifth harmonic tuning system, for example known from US. Pat. No. 3,500,116, in which a fifth harmonic is superposed on a fundamental harmonic, is commonly employed as a means for reducing the internal impedance of high voltage transformer devices. The presentinvention will be compared with a high voltage transformer device adapted to operate with such a system.

In the high voltage transformer device employing the fifth harmonic tuning system, the ratio of the voltage E appearing across the high-voltage coil to the voltage E appearing across the low-voltage coil is given y where N is the number of turns of the high-voltage coil, N is the number of turns of the low-voltage coil, and 01 0. It is thus difficult to obtain a sufficiently high output voltage; According to the present invention, the ratio of the voltage E, appearing across the high-voltage coil to the voltage E appearing across the low-voltage coil is given by where N is the number of turns of the high-voltage coil, M, is the number of turns of the low-voltage coil, and a 0. Thus, a sufficiently high output voltage can be easily obtained and yet the internal impedance can be sufficiently reduced.

Further, the high voltage transformer device employing the fifth harmonic tuning system operates with poor efficiency due to the fact that a larger power input is the order of 1.2 to 2.5 megohms, whereas the value required than when such a system is not employed provided that the load is the same. The present invention is entirely free from such a problem.

2. A focusing voltage of satisfactory trackability can be supplied from the high voltage transformer device of the present invention. I

in a prior art horizontal output circuit employing a transistor as an active element, an especially large turns ratio has been required between the low-voltage coil and the high-voltage coil of the high voltage transformer. When a focusing power supply is tapped from an intermediate point of the high-voltage coil of the high voltage transformer, the trackability of the focusing voltage has been very unsatisfactory as seen in FIG.

, 8 and such a focusing power supply could not be practically used. It has therefore been common practice to supply the focusingvoitage by dividing the high output voltage of the high voltage transformer by a resistor. However, this system has been defective among others in that the voltagedividing resistor must have a very high resistance and must be sufficiently insulated and the circuitry becomes quite complex. The present invention overcomes these defects and can provide a focusing voltage of satisfactory tracitability.

Further, in a system employing a Cockcroft circuit for rectifying and increasing the high voltage output of the high voltage transformer, a method has been generally employed in which a focusing voltage is supplied from the cathode of the diode in the first stage. it has however been experimentally confirmed that the tracltability obtained with the present invention is far better than that obtained with such a system. in the case of the Cockcroft system in which rectifiers are arranged in, for example, three stages also called doublar, the high output voltage E4, of the system in the no-load state is given by where E is the output voltage of the high voltage transformer in the no-ioad state and E is the overshoot voltage of the output of the high voltage trans= former in the no-ioad state. The focusing voltage E}, in the no load state is given by m sra On the other hand, the high voltage output E of the sys= former in the loaded state.

However, in view of the relation The trackability of the focusing voltage is the best when the above ratio is equal to 1. However, the above ratio tends to deviate greatly from 1 resulting in apoor trackability.

It will be apparent from the above description referring to only two remarkable advantages of the present invention, that the present invention is quite novel and improves over prior art devices of this kind.

What we claim is:

1. A- high voltage transformer device in a horizontal deflection circuit comprising a low-voltage coil, a core, a high-voltage coil including a high-voltage side winding and a low-voltage side winding, and a first rectifier,

wherein the high-voltage side winding of said highvoltage coil is more closely magnetically coupled to said low-voltage coil than the magnetic coupling between the low-voltage side winding of said high-voltage coil and said low-voltage coil.

2.A high voltage transformer device in a horizontal deflection circuit comprising a low-voltage coil, a core, a high-voltage coil including a high-voltage side winding and a low-voltage side winding, and a first rectifier, wherein said high-voltage coil and said low-voltage coil are disposed so that the ratio V /n between the voltage V induced in the high-voltage side winding of said high-voltage coil and the number of turns n thereof is smaller than the ratio VL/n between the voltage V induced in the low-voltage side winding of said highvoltage coil and the number of turns n thereof, hence 3. A high voltage transformer device as claimed in claim 1, wherein the relation between the ratio Eur/E between the voltage E induced in said highwoltage coil and the voltage E induced in the low-voltage coil and the ratio N /N between the number of turns N of said high-voltage coil and the number of turns N of said low-voltage coil is given by ur/ 0 X n/Nt). wh r 6. A high voltage transformer device as claimed in claim 1, wherein said low voltage coil, said core, said high=voltage coil and said first rectifier are housed within a casing, and the remaining space within the easing is filled with insulating oil.

7. A high voltage transformer device as claimed in claim 1, wherein said high=voitage coil includes a split winding.

8. A high voltage transformer device as claimed in claim 6, wherein said high=voltage coil includes a split winding.

9. A high voltage transformer device as claimed in claim 1, wherein a stepped bobbin having a large diam eter portion and a small diameter portion is employed, and the high=voltage side winding and low voltage side winding of said high-=voltage cell are wound around the 9 large and small diameter portions respectively of said bobbin.

10. A high voltage transformer device as claimed in claim 6, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed,

and the high-voltage side winding and the low voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

iii. A high voltage transformer device as claimed in claim 7, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions'respectively of said bobbin. 7

12. A high voltage transformer device as claimed in claim 4, wherein said low-voltage coil is divided into a main winding and an auxiliary winding which are closely magnetically coupled to the high-voltage side winding of said high-voltage coil and said focusing coil ur/ C (NH/NL), where 14. A high voltage transformer device as claimed in I claim 2, wherein a focusing coil is additionally provided and the relation V /n V /n is provided the ratio VF/"p being between the voltage V induced in said focusing. coil and the number of turns "p thereof and the ratio V /n being between the voltage V induced in the high-voltage side winding of said high-voltage coil and the numberof turns n thereof.

15. A high voltage transformer device as claimed in claim l4, wherein the first end of said high-voltage coil adjacent to a ground potential portion is connected to said focusing coil through a second rectifier and to the ground potential portion through a capacitive element.

16. A high voltage transformer device as claimed in claim 2, wherein said low-voltage coil, said core, said high-voltage coil and said first rectifier are housed within a casing, and the remaining space within the easing is filled with insulating oil.

17. A high voltage transformer device as claimed in claim 2, wherein said high-voltage coil includes a split winding.

18. A high voltage transformer device as claimed in claim 16, wherein said high-voltage 'coil includes a split winding.

19. A high voltage transformer device as claimed in claim 2, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

20. A high voltage transformer device as claimed in claim 16, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the lowvoltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

2.1. A high voltage transformer device as claimed in claim 17, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the lowvoltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

22. A high voltage transformer device as claimed in claim 14, wherein said low-voltage coil is divided into a main winding and an auxiliary winding which are closely magnetically coupled to the high-voltage side winding of said high-voltage coil and said focusing coil respectively.

23. A high voltage transformer device as claimed in claim 1, wherein said high-voltage coil includes a honeycomb winding.

' 24. A high voltage transformer device as claimed in claim 1,'wherein said high-voltage coil includes a bank winding.

25. A high voltage transformer device as claimed in claim 6,wherein said high-voltage coil includes a honeycomb winding. v I

26. A high voltage transformer device as claimed in 4 claim 6, wherein said high-voltage coil includes a bank winding,

27. A high voltage transformer device as claimed in claim 1, wherein a tapered bobbin having a large diameter portion and asmall diameter portion is employed, and the high-voltage side winding and low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

28. A high voltage transformer device as claimed in claim 6, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

29.v A high voltage transformer-device as claimed in claim 7, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

30. A high voltage transformer device as claimed in claim 2, wherein said high-voltage coil includes a honeycomb winding.

31. A high voltage transformer device as claimed in claim 2, wherein said high-voltage coil includes a bank winding. A

32. A high voltage transformer device as claimed in claim 16, wherein said high-voltage coil includes a honeycomb winding.

33. A high voltage transformer device as claimed in claim 16, wherein said high voltage coil includes a bank winding.

34. A high voltage transformer device as claimed in claim 2, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around 12 36. A high voltage transformer device as claimed in claim 17, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the lowvoltage side winding of-said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

Claims

1. A high voltage transformer device in a horizontal deflection circuit comprising a low-voltage coil, a core, a high-voltage coil including a high-voltage side winding and a low-voltage side winding, and a first rectifier, wherein the high-voltage side winding of said high-voltage coil is more closely magnetically coupled to said low-voltage coil than the magnetic coupling between the low-voltage side winding of said high-voltage coil and said low-voltage coil.

2. A high voltage transformer device in a horizontal deflection circuit comprising a low-voltage coil, a core, a high-voltage coil including a high-voltage side winding and a low-voltage side winding, and a first rectifier, wherein said high-voltage coil and said low-voltage coil are disposed so that the ratio VH/nH between the voltage VH induced in the high-voltage side winding of said high-voltage coil and the number of turns nH thereof is smaller than the ratio VL/nL between the voltage VL induced in the low-voltage side winding of said high-voltage coil and the number of turns nL thereof, hence VL/nL > VH/nH.

3. A high voltage transformer device as claimed in claim 1, wherein the relation between the ratio EHT/EC between the voltage EHT induced in said high-voltage coil and the voltage EC induced in the low-voltage coil and the ratio NH/NL between the number of turns NH of said high-voltage coil and the number of turns NL of said low-voltage coil is given by EHT/EC (1 + Alpha )(NH/NL), where Alpha > O.

4. A high voltage transformer device as claimed in claim 1, wherein a focusiNg coil is additionally provided and is less closely magnetically coupled to said low-voltage coil than the magnetic coupling between the high-voltage side winding of said high-voltage coil and said low-voltage coil.

5. A high voltage transformer device as claimed in claim 4, wherein the first end of said high-voltage coil adjacent to a ground potential portion is connected to said focusing coil through a second rectifier and to the ground potential portion through a capacitive element.

6. A high voltage transformer device as claimed in claim 1, wherein said low-voltage coil, said core, said high-voltage coil and said first rectifier are housed within a casing, and the remaining space within the casing is filled with insulating oil.

7. A high voltage transformer device as claimed in claim 1, wherein said high-voltage coil includes a split winding.

8. A high voltage transformer device as claimed in claim 6, wherein said high-voltage coil includes a split winding.

9. A high voltage transformer device as claimed in claim 1, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

10. A high voltage transformer device as claimed in claim 6, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

11. A high voltage transformer device as claimed in claim 7, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

12. A high voltage transformer device as claimed in claim 4, wherein said low-voltage coil is divided into a main winding and an auxiliary winding which are closely magnetically coupled to the high-voltage side winding of said high-voltage coil and said focusing coil respectively.

13. A high voltage transformer device as claimed in claim 2, wherein the relation between the ratio EHT/EC between the voltage EHT induced in said high-voltage coil and the voltage EC induced in said low-voltage coil and the ratio NH/NL between the number of turns NH of said high-voltage coil and the number of turns NL of said low-voltage coil is given by EHT/EC (1 + Alpha ) (NH/NL), where Alpha > O.

14. A high voltage transformer device as claimed in claim 2, wherein a focusing coil is additionally provided and the relation VF/nF > VH/nH is provided the ratio VF/nF being between the voltage VF induced in said focusing coil and the number of turns nF thereof and the ratio VH/nH being between the voltage VH induced in the high-voltage side winding of said high-voltage coil and the number of turns nH thereof.

15. A high voltage transformer device as claimed in claim 14, wherein the first end of said high-voltage coil adjacent to a ground potential portion is connected to said focusing coil through a second rectifier and to the ground potential portion through a capacitive element.

16. A high voltage transformer device as claimed in claim 2, wherein said low-voltage coil, said core, said high-voltage coil and said first rectifier are housed within a casing, and the remaining space within the casing is filled with insulating oil.

18. A high voltage transformer device as claimed in claim 16, wherein said high-voltage coil includes a split winding.

20. A high voltage transformer device as claimed in claim 16, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

21. A high voltage transformer device as claimed in claim 17, wherein a stepped bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

24. A high voltage transformer device as claimed in claim 1, wherein said high-voltage coil includes a bank winding.

25. A high voltage transformer device as claimed in claim 6, wherein said high-voltage coil includes a honeycomb winding.

26. A high voltage transformer device as claimed in claim 6, wherein said high-voltage coil includes a bank winding.

27. A high voltage transformer device as claimed in claim 1, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

29. A high voltage transformer device as claimed in claim 7, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

31. A high voltage transformer device as claimed in claim 2, wherein said high-voltage coil includes a bank winding.

34. A high voltage transformer device as claimed in claim 2, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.

35. A high voltage transformer device as claimed in claim 16, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound aRound the large and small diameter portions respectively of said bobbin.

36. A high voltage transformer device as claimed in claim 17, wherein a tapered bobbin having a large diameter portion and a small diameter portion is employed, and the high-voltage side winding and the low-voltage side winding of said high-voltage coil are wound around the large and small diameter portions respectively of said bobbin.