JP2001229853A - Deflection yoke and cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deflection yoke for allowing a reduction in a size and power consumption and a cathode ray tube provided with the same. SOLUTION: There is arranged an auxiliary coil 11 for inducing a magnetic field of vertical direction at the arrangement portion 3 of a vertical deflection coil V. The deflection yoke designed to let the auxiliary coil 11 (L5, L6) generate induced magnetic fields in opposite directions on an electron gun side B and on a fluorescent surface side A and a cathode ray tube provided with the deflection yoke are configured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke and a cathode ray tube having the deflection yoke.

[0002]

2. Description of the Related Art In a color cathode ray tube, a deflection yoke is provided outside a cathode ray tube to generate a deflection magnetic field so that an electron beam emitted from an electron gun is applied to a predetermined position on a phosphor screen. Electromagnetic deflection.

[0003] The deflection yoke is set so as to have a deflection center so that a neck shadow described later does not occur. Specifically, the deflection center is determined by the position where the deflection yoke is attached to the cathode ray tube.

[0004] The deflection center is a virtual center point relating to the deflection of the electron beam, and is generally located near the position of the center of the magnetic field distribution of the deflection magnetic field. When the center of the deflection magnetic field distribution changes, the deflection center changes accordingly. Therefore, if the center of the magnetic field distribution of the deflecting magnetic field is set too close to the electron gun, the electron beam emitted toward the corner of the display screen of the cathode ray tube collides with the inner wall surface of the cathode ray tube body during traveling. As a result, the running of the electron beam is hindered at the corner, and a neck shadow occurs.

For this reason, in the deflection yoke, the length of the deflection coil is extended to the fluorescent screen side as compared with the length of the neck portion of the cathode ray tube, so that the deflection center is located at a predetermined position or more on the fluorescent screen side of the cathode ray tube. It is set to effectively avoid neck shadows.

[0006]

However, when the center of deflection is set on the phosphor screen side in this way, it is necessary to increase the angle at which the electron beam is bent, thereby increasing the deflection magnetic field, that is, the so-called deflection current. Need to be larger. For this reason, the power consumption of the deflection yoke increases.

In the case where the deflection coil is extended to the fluorescent screen side of the cathode ray tube, the diameter of the cathode ray tube increases from the neck to the funnel, so that the diameter of the front end of the deflection yoke must be increased accordingly. As a result, the overall shape of the deflection yoke becomes larger, and the weight also increases. In addition, since the distance from the electron beam to the deflection yoke is long, the deflection sensitivity is deteriorated.

In order to solve the above-mentioned problems, the present invention provides a deflection yoke capable of reducing the size and power consumption, and a cathode ray tube provided with the deflection yoke.

[0009]

A deflection yoke according to the present invention comprises:
An auxiliary coil that induces a magnetic field in the vertical direction is arranged in the arrangement portion of the vertical deflection coil, and the auxiliary coil generates an induced magnetic field in the opposite direction on the electron gun side and the fluorescent screen side.

In the cathode ray tube according to the present invention, an auxiliary coil for inducing a vertical magnetic field is disposed at a position where the vertical deflection coil is disposed, and the auxiliary coil generates an induced magnetic field in the opposite direction on the electron gun side and the fluorescent screen side. This is provided with a deflection yoke.

According to the above-described configuration of the deflection yoke of the present invention, the auxiliary coil generates an induced magnetic field in the opposite direction on the electron gun side and the fluorescent screen side. One generates an induced magnetic field that cancels out the deflection magnetic field by the deflection yoke, and the other generates a magnetic field that strengthens the deflection magnetic field, and changes the distribution of the deflection magnetic field to move the position of the deflection center to, for example, the fluorescent screen side. can do. This makes it possible to adjust the position of the deflection center, for example, by controlling the amount of current flowing through the auxiliary coil.

According to the structure of the cathode ray tube of the present invention described above,
By providing the deflection yoke, the distribution of the deflection magnetic field by the deflection yoke is changed by the induced magnetic field generated by the auxiliary coil, so that the center of deflection can be easily adjusted. This makes it possible to prevent neck shadows from occurring and to improve deflection efficiency.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an auxiliary coil for inducing a vertical magnetic field is disposed in a portion where a vertical deflection coil is disposed, and an induced magnetic field in opposite directions is generated on the electron gun side and the fluorescent screen side by the auxiliary coil. This is a deflection yoke adapted to be used.

The present invention also provides the deflection yoke, wherein:
A configuration is provided in which means for changing the induced current is provided according to the absolute value of the current flowing through the vertical deflection coil.

According to the present invention, in the deflection yoke,
The magnitude of the induced magnetic field generated on the electron gun side and the fluorescent screen side is made different.

According to the present invention, an auxiliary coil for inducing a magnetic field in the vertical direction is arranged in the arrangement portion of the vertical deflection coil, and an induced magnetic field in the opposite direction is generated on the electron gun side and the fluorescent screen side by the auxiliary coil. A cathode ray tube provided with a deflection yoke.

FIG. 6 is a side view showing a partial cross section of a deflection yoke to which the present invention is applied. In FIG. 6, only the parts necessary for the description are shown on the cross-sectional side, and the description of other components is omitted.

The deflection yoke 1 is used in an assembling process.
After the horizontal deflection coil bobbin 2 and the vertical deflection coil bobbin 3 are combined, the core 4 is attached from the outside, and then the front cover 5 and the back cover 6 are attached. Here, the core 4 is disposed outside the vertical deflection coil bobbin 3 by combining two ferrite cores so as to form a substantially conical cylindrical ring core. As a result, the core 4 forms a magnetic circuit of a horizontal deflection magnetic field and a vertical deflection magnetic field, so that the deflection yoke can efficiently perform electromagnetic deflection.

A vertical deflection coil is wound on the vertical deflection coil bobbin 3 in a vertical winding step to form a vertical deflection coil assembly. Here, the vertical deflection coil is formed in a saddle shape by section winding, and when the deflection yoke 1 is arranged on the cathode ray tube, the vertical deflection coil is disposed outside the horizontal deflection coil bobbin 2 so as to sandwich the neck portion of the cathode ray tube from left and right.
It is arranged inside the core 4. Thus, the vertical deflection coil forms a vertical deflection magnetic field that crosses the neck of the cathode ray tube left and right.

On the other hand, a horizontal deflection coil is wound around the horizontal deflection coil bobbin 2 in a horizontal winding step to form a horizontal deflection coil assembly. At this time, the horizontal deflection coil winds a prescribed magnet wire using the inner side surface of the separator and the projections formed on the front end surface and the rear end surface, thereby forming a saddle type by section winding. The horizontal deflection coil is disposed inside the vertical deflection coil bobbin 3 so that when the deflection yoke 1 is disposed in the cathode ray tube, the neck portion of the cathode ray tube is sandwiched from above and below. Thereby, the horizontal deflection coil forms a horizontal deflection magnetic field that crosses the neck of the cathode ray tube up and down.

In the above configuration of the deflection yoke 1, the deflection magnetic field formed by the horizontal deflection coil and the vertical deflection coil crosses the tube axis of the cathode ray tube up and down and left and right, and then orbits the core 4 substantially half a turn. Returning to the original horizontal deflection coil and vertical deflection coil, when the polarity of the deflection current is reversed, the deflection current follows the reverse path. This deflection magnetic field changes following the change of the deflection current, and thereby the deflection yoke 1
Thus, the electron beam emitted from the electron gun can be electromagnetically deflected.

Next, as an embodiment of the present invention, FIG. 1 shows a view of a vertical deflection coil bobbin of a deflection yoke as viewed from the fluorescent screen side. In FIG. 1, a coil formed by winding a large number of electric wires is indicated by one thick wire. FIG.
Here, only parts necessary for explanation are shown.

As shown in FIG. 6, the vertical deflection coil bobbin 3 incorporates a horizontal deflection coil bobbin 2 having a horizontal deflection coil wound inside, a core 4 mounted outside, and a front cover 5 and a back cover 6 mounted thereon. This constitutes the deflection yoke 1.

A collar 8 is provided on the fluorescent screen side of the vertical deflection coil bobbin 3 so as to protrude outward from a curved surface 3a inside the vertical deflection coil bobbin 3 in the shape of a cathode ray tube. Are provided with a large number of claw-shaped protrusions 9 extending radially from the central axis. A coil having a desired shape can be easily formed by hooking an electric wire near the root of the projection 9 and performing winding.

In this embodiment, as shown in FIG. 1, a vertical deflection coil V
Separately, the auxiliary coil 11 wound in a figure eight shape has two
Are placed. That is, the first auxiliary coil L5 and the second auxiliary coil L6 are arranged.

The vertical deflection coil V has only a small part shown in FIG.
As shown in (1), the coil is wound around the vertical deflection coil bobbin 3 so that the opening of the coil is widened in the vertical direction (Y-axis direction).

On the other hand, the first auxiliary coil L5 and the second auxiliary coil L6 have a figure eight shape, and the winding method similar to the horizontal deflection coil, that is, the opening of the coil is in the horizontal direction (X-axis direction). ) Is wound around the vertical deflection coil bobbin 3.

The auxiliary coils 11 (L5, L6)
Since it is wound in the shape of a figure 8, two openings are formed: a part (A) on the near side in FIG. 1, that is, on the phosphor screen side, and a part (B) on the far side in FIG. I have.

One end of each of the first auxiliary coil L5 and the second auxiliary coil L6 is connected to each other by a wiring 12. The other end of the first auxiliary coil L5 is connected to the terminal 13A via the wiring 12, and the other end of the second auxiliary coil L6 is connected to the terminal 13B via the wiring 12.

FIG. 2 shows the vertical deflection coil bobbin 3 of FIG. 1 viewed from the Y-axis direction.
The auxiliary coil 11 (L5, L6) in the inside of FIG. Note that the broken line in FIG. 2 indicates the position of the tip end of the projection 9 instead of omitting the illustration of a large number of projections 9. As shown in FIG. 2, similar flanges 8 and projections 9 are also provided on the electron gun side of the vertical deflection coil bobbin 3 which cannot be seen in FIG.
The auxiliary coil 11 (L5, L6) is also hooked to the base of the projection 9 on the electron gun side to form a winding.

The auxiliary coil 11 is wound so that the opening of the coil is widened in the horizontal direction (X-axis direction) in the same manner as the horizontal deflection coil. An induced voltage (back electromotive voltage) is generated. Due to this induced voltage, a current tends to flow through the auxiliary coil 11 in a direction that generates a magnetic field that cancels the horizontal deflection magnetic field.

However, since the auxiliary coil 11 is wound in a figure eight shape as described above, the portion A on the phosphor screen side and the portion B on the electron gun side are viewed from the Y-axis direction as shown in FIG. When,
They are connected so that currents flow in opposite directions. Therefore, for example, when both counterclockwise currents are caused to flow due to the induced voltage, the currents of the two portions are canceled out, and the larger current amount remains and flows counterclockwise.

In the case of FIG. 2, the portion B on the electron gun side has a larger cross-sectional area in the horizontal direction of the opening than the portion A on the fluorescent screen side. . Therefore, the current I flowing through the auxiliary coil 11 directly flows counterclockwise in the portion B on the electron gun side, and the portion A on the fluorescent screen side reversely flows clockwise.

Therefore, the magnetic field generated by the current I flowing through the auxiliary coil 11 is also in the opposite direction, and one of the two portions A and B generates a magnetic field that cancels the horizontal deflection magnetic field, and the other magnetic field increases the horizontal deflection magnetic field. Occurs. In the case of the direction of the current I shown in FIG. 2, a magnetic field perpendicular to the paper surface and directed to the back is generated in the portion A on the phosphor screen side, and a magnetic field directed perpendicular to the paper surface and toward the front is generated in the portion on the electron gun side.

By utilizing this fact, the center of deflection can be moved by controlling the distribution of the horizontal deflection magnetic field as described later.

Next, the operation of moving the position of the center of deflection by changing the distribution of the horizontal deflection magnetic field using the auxiliary coils 11 (L5, L6) will be described with reference to FIG.

FIG. 3A is a diagram schematically showing a cross section in which the same vertical deflection coil bobbin 3 as in FIG. 2 is arranged so that the axial direction (Z direction) of the cathode ray tube is horizontal. FIG. 3B
3D correspond to the position of the vertical deflection coil bobbin 3 in FIG. 3A.

At this time, the horizontal deflection magnetic field .PHI.M generated by the horizontal deflection coil (not shown) has the distribution shown in FIG. 3B, and the center O1 of the horizontal deflection magnetic field .PHI.M is at the position of the chain line in FIG. 3B.

Since the auxiliary coil 11 has a large opening at the portion B on the electron gun side, the magnetic field ΦA of the auxiliary coil 11 cancels out the horizontal deflection magnetic field ΦM on the electron gun side as shown in FIG. 3C.
On the phosphor screen side, the distribution is such that the horizontal deflection magnetic field ΦM is strengthened. In this case, the intensity of the magnetic field ΦA of the auxiliary coil 11 is almost zero at the position of the center O1 of the magnetic field of the horizontal deflection magnetic field ΦM.

Therefore, by canceling the electron gun side and strengthening the fluorescent screen side with respect to the horizontal deflection magnetic field φM, a combined magnetic field φT as shown in FIG. 3D is formed, and the center O2 of the deflection magnetic field is It moves forward (on the fluorescent screen side) from the position of the center O1 of 3B. Note that the position of the center O1 of the magnetic field of the horizontal deflection magnetic field ΦM and the position where the intensity of the magnetic field ΦA of the auxiliary coil 11 becomes 0 do not necessarily have to coincide.

Then, the magnitude of the current flowing through the auxiliary coil 11 is changed to change the magnetic field Φ generated by the auxiliary coil 11.
By changing the intensity of A, the position of the center of the magnetic field of the horizontal deflection magnetic field φM can be adjusted. That is, by changing the position of the deflection center of the deflection yoke 1, the effective position can be electrically adjusted.

As described above, when the size of the induced magnetic field .PHI.A generated on the electron gun side and the fluorescent screen side is changed by changing the area of the opening of the two portions A and B of the auxiliary coil 11, as described above. In this way, the induced current I is not completely cancelled, and an induced magnetic field ΦA is generated in the opposite direction on the electron gun side and the fluorescent screen side, and the distribution of the horizontal deflection magnetic field ΦM is changed so that the position of the deflection center is shifted to one side. For example, it can move to the fluorescent screen side.

Further, if a predetermined load is connected to the auxiliary coil 11 and the load is modulated so that the impedance of the load decreases at the corner of the display screen and increases at the center of the display screen, the load is applied to the cathode ray tube. Combined magnetic field Φ
The magnetic field center O2 of T can be moved toward the phosphor screen at the corner. As described above, if the magnetic field center O2 of the synthetic magnetic field ΦT can be moved toward the phosphor screen at the corner, the deflection center can be moved toward the phosphor screen at the corner, and the margin of the corner with respect to the neck shadow is correspondingly increased. The degree can be improved. Therefore, the deflection sensitivity can be improved, and the whole can be reduced in size and weight.

In the present embodiment, the auxiliary coil 11 having the above-described structure further generates an induced current of the auxiliary coil 11 as the above-mentioned predetermined load in accordance with the absolute value of the vertical deflection current IV flowing through the vertical deflection coil V. By being connected to the saturable reactor T1 to be reduced, the amount of current flowing through the auxiliary coil 11 can be changed.

That is, as shown in the circuit diagram of FIG. 4, a saturable reactor T1 is provided as a load circuit for the auxiliary coil 11, and the saturable reactor T1 is configured to be modulated by the vertical deflection current IV. The saturable reactor T1 is formed by winding a primary winding and a secondary winding around a prescribed magnetic circuit (magnetic core), and includes a vertical deflection coil V formed by connecting two coils L3 and L4 in series. The primary windings or coils L9 and L10 are connected in series.

Also, as shown in FIG. 1, one end of each of the first auxiliary coil L5 and the second auxiliary coil L6 connected in series by the wiring 12 is connected to the other end of the saturable reactor T1. Coil L7 constituting secondary winding
And the coil L8 are connected. That is, the other end of the first auxiliary coil L5 is connected to the coil L8 via the wiring 12 and the terminal 13A, and the other end of the second auxiliary coil L6 is
It is connected to the coil L7 via the wiring 12 and the terminal 13B.

Further, as described later, the magnetic circuit is selected so that the saturable reactor T1 is saturated when the vertical deflection current IV increases and deflects near the upper and lower ends of the display screen. As a result, the impedance of the saturable reactor T1 decreases near the upper and lower ends of the display screen.
As a result, the auxiliary coil L near the upper and lower ends of the display screen
5, the current of L6 increases.

Therefore, near the upper and lower ends of the display screen,
The deflection center of the deflection yoke can be moved to the fluorescent screen side, so that the margin for the neck shadow near the upper and lower ends of the display screen can be improved.

The horizontal deflection coil H is composed of two coils L1 and L2 connected in parallel. The two coils L1 and L2 are driven by a horizontal deflection current IH and the first coil L1 is connected to the first coil L1. , And the second auxiliary coil L6 faces the other coil L2. Thus, the induced voltage is induced in the horizontal deflection magnetic field from the two coils L1 and L2, and an induced voltage is generated in the first auxiliary coil L5 and the second auxiliary coil L6.

The saturable reactor T1 is disposed, for example, on a terminal plate for relay connection between the horizontal deflection coil H and the vertical deflection coil V and the set substrate, and the horizontal deflection coil H
And the vertical deflection coil V.

Further, the specific configuration and operation of the saturable reactor T1 of FIG. 4 will be described with reference to FIG. 1 in FIG.
Reference numeral 5 denotes a magnetic circuit (magnetic core) around which the primary windings L9 and L10 and the secondary windings L7 and L8 of the saturable reactor T1 are wound.

The coils L9 and L10 constituting the primary winding of the saturable reactor T1 are connected to the primary windings L9 and L10.
When current flows through the magnetic fluxes φL9, φL10
Are wound so as to circulate through the inside of the magnetic circuit 15 in the same direction. On the other hand, the coils L7 and L8 constituting the secondary winding of the saturable reactor T1
7, L8 generated when a current flows through L8, φL7
8 are wound so as to circulate in the magnetic circuit 15 in opposite directions.

The number of turns of each of the coils L7 to L10 is such that the magnetic fluxes φL9 and φL10 generated by the coils L9 and L10 have a higher magnetic flux density than the magnetic fluxes φL7 and φL8 generated by the coils L7 and L8. And the current are set. That is, φL7, φL8 << φL9,
φL10 (1) holds.

The operation of the saturable reactor T1 is performed as follows. Since the sawtooth-shaped vertical deflection current IV synchronized with the vertical deflection flows through the coils L9 and L10 forming the primary winding of the saturable reactor T1, the vertical deflection current IV increases when it is deflected to the upper and lower ends of the screen. And the magnetic circuit 1
5 has an increased magnetic flux density.

When the magnetic flux density increases and the magnetic circuit 15 saturates, the coils L7 and L8 of the secondary winding
Becomes smaller. The coils L7 and L8 of these secondary windings are connected to the first auxiliary coil L5 and the second auxiliary coil L6 to form a series of circuits as shown in FIG. The current I due to the voltage induced by the horizontal deflection magnetic field .PHI.M flows through the auxiliary coils L5 and L6.

Further, when the inductance of the coils L7 and L8 of the secondary winding decreases, the current I flowing through the auxiliary coils L5 and L6 also increases.

When the current I flowing through the auxiliary coils L5 and L6 increases in this manner, the first auxiliary coil 11 (L5, L6)
Since the magnetic field ΦA generated by 6) increases on the phosphor screen side and decreases on the electron gun side at the same time, the horizontal deflection magnetic field ΦM on the electron gun side cancels out more than in FIG. 3D, so that the center of the deflecting magnetic field moves to the phosphor screen side. .

Therefore, when the electron beam is deflected to the corner of the display screen, the center of deflection is on the phosphor screen side (front side).
, The margin for the neck shadow increases.

As a result, in the horizontal deflection coil H and the vertical deflection coil V of the deflection yoke 1, the original deflection center moves to the electron gun side, because the margin near the upper and lower ends of the display screen with respect to the neck shadow is increased. In this manner, the positions of the fluorescent screen side and the end face of the deflection yoke can be moved to the electron gun side so that the overall length can be reduced. Accordingly, the components of the deflection yoke 1 such as the separator and the front cover 5 can be formed to have a shorter overall length or a smaller size. Thereby, the deflection sensitivity can be improved.
Further, the deflection yoke can be reduced in size and weight.

By the way, in the present embodiment, when the change in the magnetic field strength of the entire deflection magnetic field is observed before and after the saturable reactor T1 is saturated, it is found that the change after the saturation is greater than before the saturation. In addition, the change in the magnetic field strength with respect to the change in the deflection current becomes small. That is, the change in the magnetic field strength with respect to the change in the deflection current is smaller near the upper and lower ends of the display screen than in other parts of the display screen.

Considering this together with the fact that the deflection center moves to the fluorescent screen side, the deflection yoke 1 having the auxiliary coils 11 (L5, L6) according to the present embodiment has a higher efficiency than the conventional deflection yoke. As a result, the raster shape is formed in a barrel shape. In addition, since the horizontal deflection magnetic field ΦM is canceled by the current I flowing through the auxiliary coil 11, the screen size is reduced. For this reason, there is also an effect that the pincushion distortion on the left and right sides of the magnetic field is reduced.

On the other hand, in the conventional deflection yoke, the occurrence of pincushion distortion cannot be avoided. For this reason, a pin distortion correction mechanism such as a pin distortion correction magnet is provided.

According to the above-described embodiment, the back electromotive voltage is induced in the auxiliary coil 11 by the horizontal deflection magnetic field .PHI.M, and the auxiliary coil 11 is generated near the upper and lower ends of the display screen by the vertical deflection current IV. When the saturable reactor T1, which is a load circuit of, saturates, a current flows through the auxiliary coil 11 near the upper and lower ends of the display screen,
A magnetic field φA is formed by the auxiliary coil 11 so that the main magnetic field φM formed by the horizontal deflection coil H is reduced on the electron gun side.

Thus, in the vicinity of the center of the display screen, the main magnetic field ΦM formed by the horizontal deflection coil H is applied as it is as the horizontal deflection magnetic field, whereas in the vicinity of the upper and lower ends of the display screen, the auxiliary coil A combined magnetic field ΦT of the eleven magnetic field ΦA and the main magnetic field ΦM is applied as a horizontal deflection magnetic field. The resultant magnetic field ΦT is generated by the magnetic field ΦA by the induced voltage of the auxiliary coil 11 so that the main magnetic field ΦM formed by the horizontal deflection coil H is reduced on the electron gun side. As compared with the case of (1), the deflection center moves to the fluorescent screen side.

That is, an induced magnetic field is formed by the auxiliary coil 11 so that the center of deflection moves to the fluorescent screen side near the upper and lower ends of the display screen. can do. Since the neck shadow can be effectively avoided in this manner, the deflection sensitivity can be improved by setting the deflection center of the deflection yoke to the electron gun side.

Since the auxiliary coils 11 and 12 are provided on the vertical deflection coil bobbin 3 in which the vertical deflection coil V is disposed, there is no need to provide a new space for disposing the auxiliary coil, and the deflection yoke 1 has a simple configuration. Thereby, the position of the deflection center can be adjusted. Therefore, the deflection yoke 1 can be reduced in size and weight. Since the deflection yoke 1 can be reduced in size, the size and weight of the cathode ray tube can be reduced.

It is possible to simplify the manufacturing process and reduce the size of the deflection yoke.
Since the weight can be reduced, manufacturing costs and material costs can be reduced.

In the above-described embodiment, the auxiliary coil 11 wound in the shape of a figure 8 and having an opening composed of the portion A on the phosphor screen side and the portion B on the electron gun side is provided. Even if two coils are provided in such a manner that the horizontal deflection magnetic field distribution is changed, the position of the deflection center can be moved similarly. However, when two coils are divided in this way, they cannot be formed by hooking on the projections 9 of the vertical deflection coil bobbin 3. Therefore, for example, the two coils are formed by sticking them inside the vertical deflection coil bobbin. .

In this case, it is necessary to connect the two coils by wiring or the like so that opposite currents flow through the two coils so that induced magnetic fields of opposite directions are generated in the two coils. If the two coils are configured so that currents in the same direction flow, the induced magnetic field also has the same direction, so that the horizontal deflection magnetic field acts on the electron gun side and the fluorescent screen side in the same way, and This is because the effect of moving the center of the deflection magnetic field is reduced.

Even if an auxiliary coil having a single opening instead of an eight-shape is provided, the auxiliary coil is similarly connected to the variable inductor so that the amount of current flowing through the auxiliary coil can be adjusted. , The position of the deflection center can be adjusted. In this case, by increasing the opening area of the opening of the auxiliary coil, for example, by increasing the opening angle of the opening, the intensity of the magnetic field by the auxiliary coil is increased, and the position of the deflection center can be easily adjusted. Is preferred. When the opening of the auxiliary coil 11 is formed in the shape of an eight as in the above-described embodiment, an induced magnetic field ΦA that cancels one of the electron gun side and the fluorescent screen side of the horizontal deflection magnetic field ΦM and strengthens the other is used. As a result, the center of deflection can be moved more effectively than in the case where only one opening is provided.

In the above-described embodiment, the saturable reactor T1 is used as a load circuit of the auxiliary coil 11, and the saturable reactor T1 is driven by the vertical deflection current IV, so that the load of the auxiliary coil 11 is displayed on the display screen. The case where the magnetic field φA of the auxiliary coil 11 is formed by reducing the voltage near the upper and lower ends has been described. However, the present invention is not limited to this. And various load circuits can be widely applied.

In the above-described embodiment, the case where both the horizontal deflection coil and the vertical deflection coil are formed in a saddle shape by section winding has been described. However, various other configurations such as a case where the vertical deflection coil is toroidally wound, etc. Can be widely applied to the deflection yoke.

As another configuration, for example, an auxiliary coil can be formed by attaching another coil to a bobbin around which a vertical deflection coil is wound.

As described in the above embodiment, the auxiliary coil 1
Projections 9 provided on the vertical deflection coil bobbin 3
Has an advantage that the winding of the auxiliary coils 11 and 12 can be easily performed by a winding process of the vertical deflection coil V and a series of processes.

The present invention is not limited to the above-described embodiment, and may take various other configurations without departing from the gist of the present invention.

[0076]

According to the present invention described above, the induced magnetic field in the opposite direction is generated on the electron gun side and the fluorescent screen side by the auxiliary coil, so that the distribution of the deflection magnetic field is changed and the position of the deflection center is changed. Can be moved to, for example, the phosphor screen side. This makes it possible to adjust the position of the deflection center, for example, by controlling the amount of current flowing through the auxiliary coil.

When the means for changing the induced current is provided in accordance with the absolute value of the current flowing through the vertical deflection coil, the auxiliary coil is provided in accordance with the vertical position where the electron beam is deflected. By changing the flowing induced current, the magnitude of the induced magnetic field can be changed. Therefore, it is possible to adjust the position of the deflection center in accordance with the vertical position of the display screen. For example, if the deflection center moves to the fluorescent screen side near the upper and lower ends of the display screen, it is possible to improve the margin for the neck shadow near the upper and lower ends, and the deflection center of the deflection yoke is set to the electron gun. Side, the deflection sensitivity can be improved. In this case, the correction amount of the left and right pincushion distortions can be reduced.

Further, since the auxiliary coil is formed at the position where the vertical deflection coil is disposed, there is no need to provide a space for newly disposing the auxiliary coil, and the shape of the deflection yoke can be simplified. Therefore, the deflection yoke can be reduced in size and weight, and the manufacturing process can be simplified. Further, the size and weight of the cathode ray tube having the deflection yoke can be reduced.

That is, according to the present invention, the manufacturing cost and the material cost of the cathode ray tube having the deflection yoke can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a vertical deflection coil bobbin of a deflection yoke according to an embodiment of the present invention as viewed from a phosphor screen side.

FIG. 2 is a diagram showing the vertical deflection coil bobbin of FIG. 1 as viewed from the Y-axis direction, with an auxiliary coil provided therein;

FIGS. 3A to 3D are diagrams illustrating an operation of moving a position of a deflection center by changing a distribution of a horizontal deflection magnetic field using an auxiliary coil.

FIG. 4 is a circuit diagram of an auxiliary coil shown in FIG. 1;

5 is a diagram illustrating the configuration and operation of the saturable reactor shown in FIG.

FIG. 6 is a side view showing a partial cross section of a deflection yoke to which the present invention is applied.

[Explanation of symbols]

Reference Signs List 1 deflection yoke, 2 horizontal deflection coil bobbin, 3 vertical deflection coil bobbin, 4 cores, 5 front cover, 6 back cover, 8 brim, 9 protrusion, 11 auxiliary coil, 15 magnetic circuit (magnetic core), V vertical deflection coil, H horizontal Deflection coil, L1, L2, L3, L4 coil, L5 first auxiliary coil, L6 second auxiliary coil, L7, L8
Coil (of secondary winding), L9, L10 (of primary winding)
Coil, T1 saturable reactor

Claims (4)

[Claims] An auxiliary coil for inducing a magnetic field in a vertical direction is disposed at a position where a vertical deflection coil is disposed, and the auxiliary coil generates an induced magnetic field in an opposite direction on an electron gun side and a fluorescent screen side. A deflection yoke, characterized in that: 2. The deflection yoke according to claim 1, further comprising means for changing an induced current according to an absolute value of a current flowing through the vertical deflection coil. 3. The deflection yoke according to claim 1, wherein the magnitude of the induced magnetic field generated on the electron gun side and the fluorescent screen side is made different. 4. An auxiliary coil for inducing a magnetic field in a vertical direction is disposed at a position where the vertical deflection coil is disposed, and the auxiliary coil generates an induced magnetic field in an opposite direction on the electron gun side and the fluorescent screen side. A cathode ray tube comprising a deflection yoke.