JPH09199054A - Balance coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balance coil preventing a ferrite core from being easily moved when a rotary knob is touched for purposes other than the adjusting purpose by normally forming a gap between the rotary knob and a core holding member holding the ferrite core. SOLUTION: The outer screw 35 of a ferrite core 37 and the inner screw 47 of a core holding member 45 are integrally screwed together, and it is held in a balance coil bobbin 33 rotatably and unmovably in the axial direction of the bobbin 33. A rotary knob 53 is arranged concentrically with the core holding member 45 to form a gap 63. The gap 63 is normally maintained by a flexible frame 57, and the rotation of the rotary knob 53 is not transmitted to the core holding member 45. In an adjustment, the rotary knob 53 is thrust in the diameter direction of the balance coil bobbin 33, and the core holding member 45 is brought into pressure contact to transmit the rotation of the rotary knob 53. Even when the rotary knob 53 is touched for purposes other than the adjusting purpose, the ferrite core 37 is not moved easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balance coil suitable for use as a deflection coil of a cathode ray tube.

[0002]

2. Description of the Related Art In a cathode-ray tube, if the three electron beams emitted from an electron gun are not concentrated at one point, the color becomes abnormal. Therefore, the electron beam is focused on the entire screen at one point to adjust the convergence. Is done. As a kind of dynamic convergence adjustment, the correction amount of the X-axis lateral misconvergence (H amplifier) is adjusted, the left-right asymmetry of the X-axis lateral misconvergence is adjusted, or the variation of the inductance L of the two horizontal deflection coils is adjusted. There is an auxiliary convergence adjustment to correct or.

A well-known balance coil is used for this auxiliary convergence adjustment. FIG. 8 shows a sectional view of a conventional balance coil. The balance coil 1 includes a hollow balance coil bobbin 3, two coils C1 and C2 wound on both sides of the balance coil bobbin 3 at appropriate intervals, and a ferrite core 7 inserted in and out of the hollow portion 5 of the balance coil bobbin 3. have. On the outer circumference of the balance coil bobbin 3, four flange portions 9 for winding the coils C1 and C2 are provided.
Are provided with an appropriate gap. At the lower part of the two inner flange portions 9, a fixing base 11 formed by connecting them is provided.

A hexagonal through hole 13 is formed in the central portion of the ferrite core 7 over the entire length. Further, an outer screw 15 is formed on the outer circumference of the ferrite core 7. The balance coil bobbin 3 is configured such that the inside flange portion 9 is cut so that the inserted ferrite core 7 is exposed.

A rotary knob 17 is arranged between the inner collar portions 9, and an inner screw 19 of the rotary knob 17 is screwed into an outer screw 15 of the ferrite core 7. Balance coil bobbin 3
A locking portion 21 for preventing the ferrite core 7 from rotating is provided at one end of the. The locking portion 21 has a central shaft 23 having a hexagonal cross section in the center, and by inserting this into the through hole 13 of the ferrite core 7, the periphery of the ferrite core 7 is regulated.

The inductance L of this balance coil 1
To adjust, the rotary knob 17 is rotated. As a result, the ferrite core 7 is moved in the central axis direction of the balance coil bobbin 3, and the insertion length in the balance coil bobbin 3 is changed, so that the magnetic field generated by the coil is changed and the inductance L is adjusted.

[0007]

However, in the above-mentioned balance coil 1, the outer screw 1 of the ferrite core 7 is formed.
Since the rotary knob 17 in which the internal screw 19 is screwed to the protrusion 5 is projected from between the inner collar portions 9 so as to be always rotatable, after the adjustment is completed, the rotary knob 17 is used for purposes other than the purpose of the adjustment. Even when it touches, there is a problem that the rotary knob 17 is rotated and the ferrite core 7 is easily moved, so that the setting is misaligned. In addition, in order to prevent the deviation of the ferrite core 7 which is not intended for such adjustment, an adhesive may be applied over the ferrite core 7 and the balance coil bobbin 3. However, in such a method, a cured adhesive is applied. There is a problem that the removal of the agent is necessary and the readjustment becomes complicated. The present invention has been made in view of the above situation, and even if the rotary knob is touched for purposes other than adjustment,
The purpose is to provide a balance coil in which the ferrite core does not move easily.

[0008]

A balance coil according to the present invention for achieving the above object comprises a balance coil bobbin, a ferrite core inserted into a hollow portion of the balance coil bobbin and formed with an external screw, and A core hold member which is screwed onto an outer screw of the ferrite core and is supported by the balance coil bobbin so as to be freely rotatable and restricted in the axial direction of the bobbin; and an inner periphery with a gap on the outer peripheral surface of the core hold member. An annular rotary knob having a surface disposed thereon; and a flexible frame formed on the balance coil bobbin for rotatably holding the rotary knob and elastically deforming the rotary knob to allow diametrical movement. It is characterized by.

In the balance coil thus constructed, a gap is usually formed between the inner peripheral surface of the rotary knob and the outer peripheral surface of the core hold member, and the rotation of the rotary knob is directed to the core hold member. Not transmitted. Therefore, even if the rotary knob is rotated for purposes other than the purpose of adjustment, the ferrite core will not be displaced.
On the other hand, when the rotary knob is pressed in the diametrical direction, the flexible frame is elastically deformed, the rotary knob is moved in the diametrical direction, and the inner peripheral surface of the rotary knob is brought into pressure contact with the outer peripheral surface of the core hold member, and the core hold member is pressed. Can be rotated in conjunction with the rotary knob. As a result, the ferrite core is moved in the direction of the central axis of the bobbin via the outer screw, and the inductance is adjusted.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of a balance coil according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of an essential part of a balance coil according to the present invention,
2 is a front view of the rotary knob, FIG. 3 is a front view showing one end side portion of the balance coil bobbin, FIG. 4 is a side view of a bobbin collar portion on which a flexible frame is formed, and FIG. 5 is a position of the rotary knob and the core. It is explanatory drawing which shows a relationship. The balance coil 31 includes a hollow balance coil bobbin 33, two coils C1 and C2 wound on both sides of the balance coil bobbin 33 at appropriate intervals, and a ferrite core 37 inserted in and out of the hollow portion 34 of the balance coil bobbin 33. have.

On the outer periphery of the center of the balance coil bobbin 33, two flanges 3 for winding the coils C1 and C2.
9 is provided with an appropriate gap. Two collars 3
At the lower part of 9, there is provided a fixing base 41 formed by connecting the both. A hexagonal through hole 43 is formed over the entire length at the center of the ferrite core 37. An outer screw 35 is formed on the outer periphery of the ferrite core 37 over the entire length.

In the balance coil bobbin 33, a space between the two flange portions 39 is cut off so that the inserted ferrite core 37 is exposed. An annular core hold member 45 is sandwiched between the flange portions 39, and the core hold member 45 has an inner screw 47 formed on the inner side thereof and the ferrite core 3.
The outer screw 35 of 7 is screwed together. Therefore, the ferrite core 37 is connected to the core hold member 4 screwed to the outer screw 35.
The movement of the bobbin in the axial direction of the bobbin is restricted by sandwiching 5 in the collar 39.

At one end of the balance coil bobbin 33, a locking portion (not shown) for preventing the ferrite core 37 from rotating is provided. The locking part has a central shaft 5 with a hexagonal cross section in the center.
1 and is inserted into the through hole 43 of the ferrite core 37 to regulate the circumference of the ferrite core 37.

The outer periphery of the core hold member 45 is subjected to anti-slip processing such as knurling. Between the collar 39,
A ring-shaped rotary knob 53 is provided outside the core hold member 45 so as to surround the core hold member 45. Rotary knob 53
The inner diameter of the core holding member 45 is larger than the outer diameter of the core holding member 45, and the inner peripheral surface of the core holding member 45 is anti-slip such as knurled. Further, the rotary knob 53 has at least the collar portion 39.
It is formed with a more protruding outer diameter, and its outer circumference is also subjected to anti-slip processing such as knurling. As shown in FIG. 2, on both side surfaces of the rotary knob 53, projecting portions 55 that are concentric with the rotary knob 53 and project from the side surfaces are formed.

On the other hand, as shown in FIGS. 3 and 4, circular flexible frames 57 are projectingly provided on the facing surfaces of the two flanges 39, respectively. The flexible frame 57 has an inner diameter slightly larger than the outer diameter of the protruding portion 55 of the rotary knob 53, and the protruding portion 55 can be inserted inside. That is, in the rotary knob 53 disposed between the two flange portions 39, the protrusions 55 on both sides are disposed inside the flexible frame 57, so that the protrusions 55 are provided between the collar portions 39 as shown in FIG. It is supposed to be retained.

The flexible frame 57 is formed in a C-shape by separating the lower surface side of the balance coil 31 by a dividing portion 59 (see FIG. 4). Further, the semicircular arc portion of the lower half of the flexible frame 57 is separated from the collar portion 39 by the notch 61 (see FIG. 3). Therefore, the flexible frame 57 has a pair of arc portions 57a and 57b that sandwich the lower half dividing portion 59.
Is flexible in the radial direction. Flexible frame 5
7 is integrally molded with the balance coil bobbin 33 by using a flexible resin material or the like.

The rotary knob 53 held by inserting the projecting portion 55 into the flexible frame 57 is shown in FIG.
As shown in, the ferrite core 37 is arranged concentrically. Therefore, the rotary knob 53 is arranged such that the inner peripheral surface thereof has a gap 63 with the outer peripheral surface of the core holding member 45.

The balance coil 31 thus constructed
The operation of will be described with reference to FIGS. 5, 6 and 7. 6A and 6B are diagrams showing the displacement of the rotary knob. FIG. 6A shows a state in which no load is applied, FIG. 6B shows a state in which a load is applied, and FIG. 7 shows a positional relationship between the rotary knob and the core hold member during adjustment. FIG. Normally, the rotary knob 53 is arranged concentrically with the ferrite core 37 as shown in FIG. 5 by inserting the protrusion 55 into the flexible frame 57.

When the rotary knob 53 is arranged concentrically with the ferrite core 37, a gap 63 is formed between the inner peripheral surface of the rotary knob 53 and the outer peripheral surface of the core holding member 45, so that the rotary knob 53 rotates. , Is not transmitted to the core hold member 45. Therefore, as shown in FIG. 6A, in the normal state, even if the rotary knob 53 is rotated for purposes other than the purpose of adjustment, the ferrite core 37 is not displaced.

On the other hand, when adjusting the balance coil 31, the rotary knob 53 is pressed to the lower side of the balance coil 31 as shown in FIG. 6 (B). When the rotary knob 53 is pressed, the lower arc portions 57a and 57b of the flexible frame 57 are pressed.
Is elastically deformed, and the rotary knob 53 is moved downward. When the rotary knob 53 is moved downward, the inner circumference of the rotary knob 53 is pressed against the outer circumference of the core holding member 45 as shown in FIG. 7, and the rotary knob 53 is further rotated in this state, so that the core Hold member 4
5 will be rotated in conjunction with the rotary knob 53.

When the core hold member 45 is rotated, the ferrite core 37, the rotation of which is restricted by the central shaft 51 of the engaging portion, is moved in the bobbin central axis direction via the outer screw 35. As a result, in the balance coil 31, the insertion length of the ferrite core 37 in the balance coil bobbin 33 changes, the magnetic fields generated by the coils C1 and C2 change, and the inductance L is adjusted.

After the adjustment, when the pressing force of the rotary knob 53 is released, the rotary knob 53 is again arranged concentrically with the ferrite core 37 by the elastic restoring force of the flexible frame 57,
The core hold member 45 and the core hold member 45 are arranged with a gap 63, and the rotation of the rotary knob 53 is not transmitted to the core hold member 45.

As described above, according to the balance coil 31 described above, the core holding member 45 is screwed onto the outer periphery of the ferrite core 37, and the ferrite core 37 is moved between the flange portions 39 via the core holding member 45. On the other hand, the rotary knob 53 is arranged on the outer circumference of the core hold member 45 with a gap 63 therebetween so that the rotary knob 53 contacts the core hold member 45 only by a pressing force.
Since 3 is held by the flexible frame 57, a gap 63 is normally provided between the rotary knob 53 and the core hold member 45.
Is formed, touch the rotary knob 53 for purposes other than adjustment,
Even when the rotary knob 53 is rotated, the rotation is not transmitted to the core holding member 45, and the ferrite core 37 is not likely to be displaced.

Further, in order to prevent the ferrite core 37 from being displaced, the ferrite core 37 and the balance coil bobbin 3
Since it is not necessary to apply an adhesive agent to 3 and 3, it is not necessary to remove the cured adhesive agent, and readjustment can be facilitated.

[0025]

As described in detail above, according to the balance coil of the present invention, a gap is normally formed between the rotary knob and the core hold member, so that when the rotary knob is rotated. However, the rotation is not transmitted to the core holding member, and there is no fear that the ferrite core will be displaced. As a result, even if the rotary knob is touched for purposes other than adjustment, there is no concern that the ferrite core will move, and re-adjustment caused by unintentional contact with the rotary knob can be eliminated.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a balance coil according to the present invention.

FIG. 2 is a front view of a rotary knob.

FIG. 3 is a front view showing a portion on one end side of a balance coil bobbin.

FIG. 4 is a side view of a bobbin collar portion on which a flexible frame is formed.

FIG. 5 is an explanatory diagram showing a positional relationship between a rotary knob and a core.

FIG. 6 is an explanatory diagram showing displacement of a rotary knob.

FIG. 7 is an explanatory diagram showing a positional relationship between a rotary knob and a core hold member during adjustment.

FIG. 8 is a cross-sectional view of a conventional balance coil.

[Explanation of symbols]

31 Balance coil 33 Balance coil bobbin 34 Hollow part 35 External screw 37 Ferrite core 45 Core hold member 47 Internal screw 53 Rotating knob 57 Flexible frame
63 gap

Claims (1)

[Claims] 1. A balance coil bobbin, a ferrite core inserted into a hollow portion of the balance coil bobbin and having an external thread formed thereon, and an internal thread screwed onto the external thread of the ferrite core so as to be rotatable and regulated to move in a bobbin axial direction. A core hold member supported by the balance coil bobbin, an annular rotary knob having an inner peripheral surface with a gap on the outer peripheral surface of the core hold member, and the rotary knob formed on the balance coil bobbin. And a flexible frame for rotatably holding and allowing elastic movement of the rotary knob in the diametrical direction.