JP2003132819A - Deflection yoke and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deflection yoke which can correct inexpensively misconvergence generated in up and down direction of a picture without an adverse effect on other convergence characteristics. SOLUTION: The deflection yoke comprises, a conical cylinder-shaped core whose both openings are arranged on a center axis of the deflection yoke, a vertically deflecting toroidal coil wound around the core which forms barrel- shaped vertically deflecting magnetic field which deflects electron beams in a vertical direction, a pair of magnetic pieces 21A and 21B which are disposed oppositely and approximately parallel at positions that are equally apart from a horizontal axis (X-axis) of the deflection yoke via horizontal arms of the deflection yoke on a side of small opening of the core, and a holder 22 which holds the pair of magnetic pieces 21A and 21B in a body. The pair of magnetic pieces 21A and 21B can be set optionally on right or left side of a vertical axis (Y-axis) of the deflection yoke by sliding the holder 22 along the horizontal arms of the deflection yoke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device such as a television receiver or a computer display using a cathode ray tube, and more particularly to a deflection yoke (DY) mounted on the cathode ray tube.

[0002]

2. Description of the Related Art A display device using a cathode ray tube has a deflection yoke for deflecting an electron beam emitted from an electron gun. The deflection yoke has a horizontal deflection coil and a vertical deflection coil, and is used by being mounted on a cathode ray tube. In this deflection yoke, the horizontal deflection coil forms a horizontal deflection magnetic field that deflects the electron beam left and right (horizontal direction), and the vertical deflection coil forms a vertical deflection magnetic field that deflects the electron beam vertically (vertically).

In such a display device, three electron beams emitted from an electron gun are deflected vertically and horizontally by a deflection yoke, so that the spot of the electron beam becomes horizontal on the fluorescent surface of the inner surface of the panel of the cathode ray tube. And scan vertically to form a raster, and 3 at each scan position.
By focusing (converging) the electron beam of the book, it is possible to display a good image without color shift. Therefore, the three electron beams are not focused on the fluorescent screen, that is, the so-called convergence shift (hereinafter,
"Miss Convergence") occurs, this appears as a color shift on the screen.

Here, in some conventional display devices, an electron beam that emits a green (G) phosphor is used as a center beam, and each electron beam that emits red (R) and blue (B) phosphors is a side beam. Some have an in-line type color cathode ray tube as a beam. In the in-line type color cathode ray tube, a self-convergence method is used to correct color misregistration in the peripheral area of the screen by using a vertical deflection magnetic field as a barrel type and a horizontal deflection magnetic field as a pincushion type as the magnetic field distribution of the deflection yoke. ing.

However, in this type of color cathode ray tube, the positions of the three electron beams incident on the deflection yoke may shift to either the left or right side on the horizontal axis due to manufacturing assembly errors or the like. If you do, both sides 2
Since the intensity of the vertical deflection magnetic field acting on the two side beams becomes non-uniform, misconvergence (hereinafter also referred to as “upper and lower miscon”) in which the positions of the two side beams are displaced in the vertical direction of the screen occurs. As a specific example, consider the case where the positions of the three electron beams B, G, and R are displaced to the left side when viewed from the panel side, as shown in FIG. At this time, in the barrel-shaped vertical deflection magnetic field φMv, both ends on the horizontal axis (X axis) have a higher magnetic flux density than the central part. Therefore, when the positions of the electron beams B, G, and R shift to the left, the side beam B corresponding to blue passes through a region having a higher magnetic flux density than the side beam R corresponding to red.

Thus, the side beam B is deflected more than the side beam R when the beam is deflected in the vertical direction. Therefore, in the vertical direction of the screen, as shown in FIG. 7, the side beam B is sandwiched with the center beam G interposed therebetween.
, But the side beam R is displaced inward, causing misconvergence. Therefore, conventionally, the following two correction methods have been considered as means for correcting the vertical misconversion.

As shown in FIG. 8, the first correction method is a method in which a pair of correction coils L1 and L2 are provided on the rear end side of the deflection yoke so as to face each other on the horizontal axis (X axis). In this method, by changing the balance of the currents flowing through the pair of correction coils L1 and L2,
The intensity of the correction magnetic field φSv by L2 can be changed between the left and right. Therefore, for example, when the correction coil L2 on the side beam R side is caused to flow a current at a higher rate to thereby relatively increase the strength of the correction magnetic field φSv on the side beam R side, FIG. 9 is displayed on the screen. Such a convergence pattern occurs. The convergence pattern shown in FIG. 9 has side beams B and R compared to the misconvergence pattern shown in FIG.
The vertical positional relationship of is reversed. From this, under the condition that the magnetic field strength of the correction coil L2 on the side beam R side is larger than the magnetic field strength of the correction coil L1 on the side beam B side, the current balances flowing through the correction coils L1 and L2 are appropriately adjusted. This makes it possible to match the positions of the three electron beams B, G, and R in the vertical direction of the screen as shown in FIG.

The second correction method is, as shown in FIG.
This is a method of inserting a plate-shaped magnetic piece 52 from one side in the horizontal axis direction in the vicinity of the DY core 51. In this method, the magnetic piece 5
Since a strong magnetic field passing through the magnetic piece 52 is generated on the side where 2 is inserted, the strength of the vertical deflection magnetic field can be partially strengthened there. Therefore, with respect to the occurrence of the misconvergence shown in FIG. 7, as shown in FIG. 12, the magnetic piece 52 is inserted from the right side when viewed from the panel side to enhance the strength of the vertical deflection magnetic field φMv on the side beam R side. As a result, the difference between the vertical deflection amounts of the side beams B and R can be eliminated and the vertical mis-conversion can be corrected appropriately.

[0009]

However, the above-mentioned first and second correction methods have the following drawbacks. That is, in the first correction method, the pair of correction coils L1 and L2
In addition to this, since it is necessary to incorporate an expensive correction circuit using a variable resistor for current balance adjustment or the like, there is a disadvantage that the cost disadvantage is large.

Further, although the second correction method has an advantage that it can be implemented at a lower cost than the first correction method, it has a disadvantage that other convergence characteristics are adversely affected by an increase in magnetic field distortion due to the magnetic piece 52. was there. For example, when the magnetic piece 52 is inserted from the right side (side beam R side) as shown in FIG.
The increase in the magnetic field distortion due to the increase in the inclination (inclination with respect to the horizontal axis) of the vertical deflection magnetic field φMv acting on the side beam R causes the side beam R to be deflected to the right. Therefore, even if the vertical misconversion can be corrected, as shown in FIG. 13, misconvergence occurs in which the side beam R is displaced to the right in the left-right direction of the screen. Such a phenomenon becomes more prominent as the correction amount of misconvergence (vertical miscon) to be corrected originally increases.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a deflection yoke capable of inexpensively correcting vertical misconversion without adversely affecting other convergence characteristics. It is to provide a display device using this.

[0012]

A deflection yoke according to the present invention has a core having a cylindrical structure in which one side of the yoke center axis direction is larger than the other side, and the core is wound in a toroidal shape. A vertical deflection coil that forms a barrel-shaped vertical deflection magnetic field that vertically deflects an electron beam, and a pair of vertical deflection coils that are equidistant from the yoke horizontal axis on the small-diameter opening side of the core and are substantially parallel to the horizontal axis of the yoke. And a pair of magnetic pieces that can be selectively arranged on either the right or left side of the yoke vertical axis as a boundary while being opposed to each other via the horizontal axis of the yoke.

In the deflection yoke having the above structure and the display device using the deflection yoke, the yoke is paired at the upper and lower positions equidistant from the yoke horizontal axis on the small-diameter opening side, and is substantially parallel to the yoke horizontal axis. By arranging the pair of magnetic pieces so as to face each other via the horizontal axis, part of the barrel-shaped vertical deflection magnetic field formed by the vertical deflection coil forms a magnetic path passing through the pair of magnetic pieces. Become. As a result, in the peripheral region where the electron beam passes, it is possible to widen the vertical deflection magnetic field distribution without increasing the distortion of the vertical deflection magnetic field.
Therefore, by arranging the pair of magnetic pieces on either the left or right side of the vertical axis of the yoke, the side where the pair of magnetic pieces is arranged suppresses adverse effects on other convergence characteristics due to magnetic field distortion, and It is possible to weaken the strength of the vertical deflection magnetic field acting on the beam.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing an overall image of a cathode ray tube according to the present invention. In FIG. 1, the main body portion (glass bulb) of the cathode ray tube 10 is composed of a panel portion 11, a funnel portion 12 and a neck portion 13. On the inner surface of the panel portion 11, there is formed a phosphor screen (not shown) in which phosphors of red, blue and green are arranged in a pattern. On the other hand, the neck portion 13 is internally provided with an electron gun 14 that emits three electron beams in an in-line arrangement. Also, the neck 1
A deflection yoke 15 for deflecting the electron beam is mounted on the cone portion extending from 3 to the funnel portion 12.

The cathode ray tube 10 having the above-mentioned structure is provided with a panel portion 11
It is incorporated in a housing (not shown) together with various accessories necessary for reproducing a color image (or a black-and-white image) on the fluorescent surface on the inner surface, which constitutes a display device such as a television receiver or a computer display. It

FIG. 2 is a side view including a partially broken surface of the deflection yoke according to the present invention. In FIG. 2, the deflection yoke 15
The horizontal deflection coil 16, the vertical deflection coil 17, the separator 18, the DY core 19, the ring magnet 20, and other components are installed in the. The separator 18 is made of an insulating material such as resin, and is formed in a substantially trumpet shape as a whole.

The horizontal deflection coils 16 are paired above and below the deflection yoke 15 and wound in a saddle shape inside the separator 18. The horizontal deflection coil 16 forms a pincushion-shaped horizontal deflection magnetic field that deflects the electron beam to the left and right (horizontal direction) when a horizontal deflection current of a sawtooth wave is supplied from a horizontal deflection circuit (not shown). The vertical deflection coils 17 form a pair above and below the deflection yoke 15 and are wound around the DY core 19 in a toroidal shape. The horizontal deflection coil 17 forms a barrel-shaped vertical deflection magnetic field that deflects the electron beam up and down (vertical direction) when a vertical deflection current of a sawtooth wave is supplied from a vertical deflection circuit (not shown).

The DY core 19 is made of a magnetic material such as ferrite, and one side (left side in FIG. 2) in the Z-axis direction, which is the center axis of the yoke (center axis of the deflection yoke), is more than the other side (right side in FIG. 2). It is formed in a substantially conical cylindrical shape with a large opening. This DY core 19 enhances the effectiveness of the magnetic field generated by the horizontal deflection coil 16 and the vertical deflection coil 17,
It is attached to the outside of the horizontal deflection coil 16 via a separator 18. The ring magnet 20 is the electron gun 1
The deflection yoke 15 is attached to the rear end of the deflection yoke 15 in order to correct the deviation of the orbit of the electron beam due to the assembly error in FIG.

Further, as shown in FIG. 3, the deflection yoke 15 is provided with a pair of magnetic pieces 21A and 21B. The pair of magnetic pieces 21A and 21B are provided on the holder member 22.
Are held together by. The holder member 22 is integrally molded of resin, and the pair of magnetic pieces 21A and 21B is fixed (embedded) to the holder member 22 by the resin molding. The holder member 22 and the pair of magnetic pieces 21A and 21B held by the holder member 22 are arranged on the small-diameter opening side (right side in FIG. 2) of the DY core 19 in the Z-axis direction, which is the center axis of the yoke, and more specifically, on the DY core 19. The holder member 2 is provided between the end of the small-diameter opening (opening end) and the crossover portion (bend portion) 16A on the neck side of the horizontal deflection coil 16.
It is arranged with 1 inserted. In order to facilitate this inserting operation, the knob portion 2 is provided on the holder member 22.
3 is integrally formed.

On the other hand, on the outside of the neck portion (cylindrical portion) of the separator 18, a guide portion (not shown) is provided corresponding to the insertion position of the holder member 22. The guide portion engages with the holder member 22 inserted from the X-axis direction, which is the horizontal axis of the yoke (horizontal axis of the deflection yoke), for example, by combining the upper end portion and the lower end portion of the holder member 22 with the combination of the uneven structure. By (fitting), the holder member 22 is slidably supported in the X-axis direction. The guide members are provided on both the left and right sides on the X axis, so that the holder member 22 can be inserted from either the left or the right. When the holder member 22 is inserted from the left side, the pair of magnetic pieces 21A and 21B are also arranged on the left side, and when the holder member 22 is inserted from the right side, the pair of magnetic pieces 21 is inserted.
A and 21B are also arranged on the right side. In other words, the pair of magnetic pieces 21A and 21B can be selectively arranged on either the left or right side of the Y axis that is the yoke vertical axis (vertical axis of the deflection yoke).

When the holder member 22 is engaged with the guide member, the vertical position of the holder member 22 and the insertion end position are restricted by the guide member. Also,
The slide movement of the holder member 22 along the X-axis direction is allowed between the insertion start end position and the insertion end position, and the pair of magnetic pieces 21A and 21B also move integrally with the holder member 22 during this slide movement. However, since the pair of magnetic pieces 21A and 21B are integrally held by the holder member 22, even if the holder member 22 is slid in the X-axis direction, the positional relationship between the magnetic pieces 21A and 21B in the vertical direction is constant. Retained. In addition, the holder member 22
In the state where the magnetic pieces 21A and 21B are inserted to the insertion end position, the end portions Pa and Pb of the magnetic pieces 21A and 21B are arranged near the Y axis on the insertion side. In FIG. 3, the arrangement state when the holder member 22 is inserted from the right side (side beam R side) when viewed from the panel side is shown by a solid line, while the holder member 22 is inserted from the left side (side beam B side). The arrangement state at this time is shown by a two-dot chain line. It should be noted that when the holder member 22 is inserted to the end position, the end portions Pa and Pb of the magnetic pieces 21A and 21B may slightly protrude beyond the Y axis to the opposite side. .

Further, in the state where the holder member 22 is inserted as described above, the pair of magnetic pieces 21A, 21B are
They are arranged so as to face each other with the shaft interposed therebetween. Each of the magnetic pieces 21A and 21B is made of a soft magnetic material such as electromagnetic soft iron, sendust, permalloy, electromagnetic stainless steel, and ferrite, and is formed in an elongated plate shape or a rod shape, respectively. Of these, the magnetic piece 21A is arranged above the deflection yoke and substantially parallel to the X axis, and
1B is disposed below the deflection yoke and substantially parallel to the X axis. Therefore, in the holder member 22 alone, the pair of magnetic pieces 21A and 21B are held in parallel with each other along the inserting direction of the holder member 22. On the other hand, Y
In the axial direction, the pair of magnetic pieces 21A and 21B are arranged equidistantly from the X axis, and the pair of magnetic pieces 2
The distance between 1A and 21B is set to be substantially equal to the diameter of the separator neck portion.

Next, the deflection yoke 15 having the above structure
The correction principle in the case of correcting the upper and lower miscons by using will be described. First, as a specific example, as shown in FIGS. 6 and 7 described above, this occurs when the positions of the three electron beams B, G, and R incident on the deflection yoke are shifted to the left when viewed from the panel side. When correcting the misconvergence, the holder member 2
By inserting 2, the pair of magnetic pieces 21A and 21B is arranged on the left side as shown in FIG.

As a result, the pair of magnetic pieces 21A, 21B
On the left side where is arranged, a part of the barrel-shaped vertical deflection magnetic field formed by the vertical deflection coil 17 is attracted to the magnetic pieces 21A and 21B having high magnetic permeability. for that reason,
A part of the vertical deflection magnetic field forms a magnetic path passing through the pair of magnetic pieces 21A and 21B. Since this magnetic path is formed along the direction (X axis) of the pair of magnetic pieces 21A and 21B, the distortion of the vertical deflection magnetic field can be suppressed small in the peripheral region where the side beam B passes. Further, in the peripheral region where the side beam B passes, part of the vertical deflection magnetic field is attracted to the pair of magnetic pieces 21A and 21B, so that the magnetic field distribution is expanded in the vertical direction. Therefore, the magnetic flux density becomes low in the portion where the magnetic field distribution is widened, and the magnetic field strength acting on the side beam B becomes weaker accordingly.

As a result, on the left side where the pair of magnetic pieces 21A and 21B are arranged, it is possible to weaken the strength of the vertical deflection magnetic field acting on the side beam B while suppressing adverse effects on other convergence characteristics due to the magnetic field distortion as much as possible. it can. As a result, when the positions of the electron beams B, G, and R are displaced to the left, the increase in the intensity of the vertical deflection magnetic field acting on the side beam B due to the displacement of the beam positions is increased by the magnetic field intensity of the pair of magnetic pieces 21A and 21B. Of the vertical deflection magnetic field acting on the side beams B and R can be made uniform. Therefore, it is possible to appropriately correct the vertical misconversion without causing the side beam to be displaced in the horizontal direction on the screen. In particular, each of the magnetic pieces 21A and 21B is formed into an elongated plate shape or a rod shape, and thereby the length dimension (longitudinal dimension) of the magnetic pieces 21A and 21B is secured long in the direction parallel to the X-axis, so that the magnetic field distortion is prevented. It is possible to obtain a sufficient amount of convergence correction while effectively suppressing the adverse effect on other convergence characteristics due to.

By the way, when the positions of the three electron beams B, G and R are shifted to the right side when viewed from the panel side, the side beams are arranged by arranging the pair of magnetic pieces 21A and 21B accordingly. Since the strength of the vertical deflection magnetic field is weakened on the R side, the vertical misconversion can be appropriately corrected in the same manner as above.

Further, the pair of magnetic pieces 21A and 21B are moved to the X-axis by the sliding movement of the holder member 22 along the X-axis direction.
With the axially movable structure, the positions of the pair of magnetic pieces 21A and 21B can be finely adjusted on the side where the holder member 22 is inserted (left side or right side). Thereby, the convergence correction amount by the pair of magnetic pieces 21A and 21B can be arbitrarily changed. Furthermore, it is possible to change the magnetic correction range by changing the size of each of the magnetic pieces 21A and 21B, especially the longitudinal dimension.

In the above embodiment, the holder member 22 that integrally holds the pair of magnetic pieces 21A and 21B.
By inserting (inserting) from the X axis direction, the pair of magnetic pieces 21A and 21B can be selectively arranged on either the left or right side (left side or right side) with the Y axis as a boundary. Other than this, for example, as shown in FIG. 5, a pair of magnetic pieces 21A and 21B are fixed to the upper and lower sides of a frame-shaped holder member 22 and integrally held, and the holder member 22 is attached to the outer peripheral side of the separator neck portion. By engaging and supporting slidably in the X-axis direction, a pair of magnetic pieces 21A, 21 is provided on either the left or right side (left or right) with the Y-axis as a boundary.
B may be selectively arranged.

In the structure shown in FIG. 5, when the positions of the three electron beams B, G, and R are displaced to the left when viewed from the panel side, the pair of magnetic pieces 21A and 21B are moved by the sliding operation of the holder member 22. If the positions of the three electron beams B, G, and R are displaced to the right side when viewed from the panel side, the pair of magnetic pieces 21A and 21B are disposed to the right side by the slide operation of the holder member 22. As in the above embodiment, the vertical misconversion can be properly corrected.

[0031]

As described above, according to the present invention, a pair of upper and lower positions, which are equidistant from the yoke horizontal axis on the small diameter opening side of the core, are arranged substantially parallel to the yoke horizontal axis and the yoke horizontal axis. By arranging the pair of magnetic pieces so as to face each other with the pair of magnetic pieces on either the left or right side of the yoke vertical axis as a boundary, the other convergence characteristics are not adversely affected. By using an inexpensive correction method using a pair of magnetic pieces, it is possible to appropriately correct the vertical misconversion.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an overall image of a cathode ray tube according to the present invention.

FIG. 2 is a side view including a partial fractured surface of a deflection yoke according to the present invention.

FIG. 3 is an enlarged front view of the main part of the deflection yoke according to the embodiment of the present invention.

FIG. 4 is a front view showing an arrangement example of a pair of magnetic pieces corresponding to a position shift of an electron beam.

FIG. 5 is a front view of a main part showing another embodiment of the present invention.

FIG. 6 is a diagram showing an example of a position shift state of an electron beam.

FIG. 7 is a diagram showing an example of occurrence of misconvergence due to displacement of an electron beam.

FIG. 8 is a diagram illustrating a first conventional correction method.

FIG. 9 is a diagram showing an example of a convergence pattern obtained by the first correction method.

FIG. 10 is a diagram showing a convergence pattern in a properly corrected state.

FIG. 11 is a diagram illustrating a second conventional correction method.

FIG. 12 is a diagram showing an arrangement example of magnetic pieces in the second correction method.

FIG. 13 is a diagram showing an example of a convergence pattern after correction by the second correction method.

[Explanation of symbols]

10 ... Cathode ray tube, 11 ... Panel section, 12 ... Funnel section, 13 ... Neck section, 14 ... Electron gun, 15 ... Deflection yoke, 16 ... Horizontal deflection coil, 17 ... Vertical deflection coil, 1
8 ... Separator, 19 ... DY core, 21A, 21B ... Magnetic piece, 22 ... Holder member

Claims (4)

[Claims] 1. A core having a cylindrical structure in which one side of a yoke central axis direction is opened larger than the other, and a barrel type vertical coil which is wound around the core in a toroidal shape and deflects an electron beam in a vertical direction. A state in which a vertical deflection coil that forms a deflection magnetic field is paired with a vertical position equidistant from the yoke horizontal axis on the side of the small-diameter opening of the core so as to be substantially parallel to the yoke horizontal axis and face each other through the yoke horizontal axis. And a pair of magnetic pieces that can be selectively arranged on either the left or right side of the vertical axis of the yoke as a boundary. 2. The deflection yoke according to claim 1, wherein the pair of magnetic pieces are movable in a horizontal axis direction of the yoke. 3. A core having a cylindrical structure in which one side of the yoke central axis direction is opened larger than the other, and a barrel type vertical winding which is wound in a toroidal shape on the core and deflects an electron beam in a vertical direction. A state in which a vertical deflection coil that forms a deflection magnetic field is paired with a vertical position equidistant from the yoke horizontal axis on the side of the small-diameter opening of the core so as to be substantially parallel to the yoke horizontal axis and face each other through the yoke horizontal axis. And a pair of magnetic pieces that can be selectively arranged on either the left or right side of the vertical axis of the yoke as a boundary, and the deflection yoke is mounted on the cathode ray tube. 4. The display device according to claim 3, wherein the pair of magnetic pieces are movable in the yoke horizontal axis direction.