JPH0795602A - Deflecting yoke device for color picture tube - Google Patents

Abstract

PURPOSE:To eliminate or reduce the raster shift and the lending shift of the earth magnetism when a picture tube device set in the east is changed to the north or the south end to obtain the color images of high quality that are free from the color turbidity. CONSTITUTION:A pair of correction coils 12A and 12B having the prescribed engles in the horizontal direction end against a plane vertical to the axis of a color picture are placed at the front or rear edge of a coil bobbin 2 of a color picture tube deflecting yoke device 1. In such a constitution, it is possible to cancel the earth magnetism in the axial direction of the color image tube by energizing both coils 12A and 12B and also to keep the east magnetic state even in the north or south direction by generating a magnetic field in the horizontal direction.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a color television receiver, C
The present invention relates to a deflection yoke device for a color picture tube used in an RT display device or the like.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show a deflection yoke device for a color picture tube in the prior art, and FIGS. 6 to 8 show a raster changing state of the deflection yoke in the prior art.

In the figure, reference numeral 1 denotes a conventional deflection yoke device for a color picture tube. This deflection yoke device 1a for a color picture tube is formed by expanding a resin material in a bosh shape, and a front end enlarged portion 2A and a rear end portion are formed. A coil bobbin 2 having an enlarged portion 2B, a core 3 provided on the outer peripheral side of the coil bobbin 2, a pair of horizontal deflection coils 4 and 4 provided on the inner peripheral side of the coil bobbin 2, and winding or inside the core 3. Vertical deflection coil 5 provided in the
It is generally composed of a geomagnetic correction coil 12 provided so as to be wound around a surface perpendicular to the tube axis of the picture tube 6. The deflection yoke device 1a is attached to the neck portion 6A of the color picture tube.

In the conventional technique thus constructed, the electron beam 9 is emitted from three color electron guns (not shown) provided in the neck portion 6A of the color picture tube 6. The electron beam 9 is deflected by the horizontal deflection coil 4 and the vertical deflection coil 5, passes through a shadow mask (not shown) provided inside the color picture tube 6, and then approaches the screen 6B of the color picture tube 6. Each of the red, green, and blue phosphor dots 8 provided on the formed phosphor screen 6C has an electron beam 9
Is supposed to hit.

Such a color picture tube device has a screen 6B of the color picture tube 6 as shown in FIG.
The upper raster pattern 10 (hereinafter referred to as raster) becomes a normal screen 6B without rotation and vertical movement. However, when the screen 6B is turned northward from this state, the geomagnetism acting from left to right in the drawing when facing east disappears, and the neck side of the color picture tube 6 is newly acted on the face side. This change in the geomagnetism affects the electron beam 9, and the electron beam 9 is displaced upward and twisted counterclockwise. As a result, the color picture tube 6
Raster 10 on drawing 6B of FIG. 6 moves from X, Y to X ', Y' as shown in FIG.

On the contrary, when the screen 6B is turned to the south, the geomagnetism from the left to the right of the drawing disappears as in the case of facing north, and the face of the color picture tube 6 moves from the face side to the neck side, contrary to the case of facing north. Geomagnetism is added. This causes the electron beam 9 to move upward and rotate clockwise.

FIGS. 9, 10, and 11 are enlarged views of the 1-dot trio at the upper left portions a, b, and c of the screen 6B shown in FIGS. 6, 7, and 8, respectively. In the eastern direction shown in FIG. 9, as described above, each electron beam 9 accurately hits the dot 8 of each phosphor. On the other hand, as shown in FIG. 10, in the north direction, the geomagnetism acting from the left to the right of the drawing disappears, and the geomagnetism from the neck side of the color picture tube 6 to the fence side newly acts, The electron beam 9 moves in the direction directly above and shifts to the lower left direction, and the electron beam 9 shifts in the lower left direction as a total, causing a so-called landing mistake.

Further, as shown in FIG. 11, in the southward direction, the geomagnetism from the left side to the right side of the drawing disappears, and the geomagnetism from the face side to the neck side of the color picture tube 6 is further added. As a result, the electron beam 9 moves right above and at the same time moves to the upper right, and is shifted to the upper right as a total.

As described above, the color picture tube 6 projects the electron beam 9 through the shadow mask and reflects it on the fluorescent screen 6C. However, due to the influence of the earth magnetism when the color picture tube device is rotated in the direction, the raster 10 is moved. At the same time, the electron beam 9 moves,
The phosphor dots 8 do not hit the phosphor dots 8 accurately, and the phosphor dots 8 as a whole do not emit light, which causes problems such as color turbidity. In the conventional method (Japanese Utility Model Laid-Open No. 3-37743) proposed to solve the above problem, as shown in FIG.
A correction coil 12 for generating a magnetic field that cancels it is attached near the coil bibon 2A or 2B of the deflection yoke device 1a so as to be wound around the correction coil coil bobbin 11a around the tube axis of the color picture tube 6.
This correction coil is wound around the correction coil coil bobbin 11 for several turns as shown in FIG.
3, the DC power supply 14, and the variable resistor 15 are connected in series.

When the color picture tube device is facing north, a magnetic field in the B direction is generated by passing an electric current in the direction of FIG. 5A to cancel the geomagnetism from the neck side to the face side. As shown in FIG. 14, it is possible to reduce or eliminate the rotation except the vertical movement of the raster 10 and the deviation in the rotation direction except the vertical deviation of the landing.

On the other hand, when facing south, a magnetic field in the D direction is generated by passing an electric current in the direction of FIG. 5C to cancel the geomagnetism traveling from the face side to the neck side.
As shown in FIG. 15 and FIG. 15, it is possible to reduce or eliminate the rotational displacement of the raster 10 excluding the vertical movement and the rotational displacement of the landing excluding the vertical displacement.

However, as described above, the vertical movement of the raster 10 and the vertical movement of the landing due to the disappearance of the geomagnetism from the left to the right of the drawing cannot be corrected.

[0013]

As described above, in the prior art, the magnetic field in the tube axis direction can be canceled or the magnetic field in the horizontal direction cannot be corrected, so that X to X'as shown in FIGS. Displacement of the raster 10 in the upward direction,
An upward landing shift as shown in FIGS. 14 and 15 remains.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a deflection yoke device for a color picture tube having a function capable of simultaneously correcting the magnetic field in the tube axis direction and the magnetic field in the horizontal direction.

[0015]

In order to solve the above-mentioned problems, the deflection yoke device of the present invention has a coil bobbin having a predetermined front end side or a rear end side, which is provided in a predetermined direction in the horizontal direction with respect to a plane perpendicular to the tube axis of the picture tube. It is characterized in that a pair of correction coils having an angle is provided.

[0016]

With the above construction, a predetermined corrected DC current is passed to cancel the geomagnetism generated in the tube axis direction of the color picture tube, and at the same time, a magnetic field from left to right is generated toward the tube surface. The same magnetic field as in the east direction or a magnetic field very close to the east direction is maintained in the direction of the south and the south,
Raster movement and landing movement due to changes in the geomagnetism can be eliminated or reduced.

[0017]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a plan view of a deflection yoke device for a color picture tube according to the present invention. In this embodiment, the same components as those of the prior art shown in FIGS.
The same reference numerals are given and the description thereof will be omitted. FIG. 11 shows a correction coil coil bobbin for winding the correction coils 12A and 12B. The correction coil coil bobbin 11 is fixed to the outer periphery of the front end enlarged portion 2A of the coil bobbin 2 with an adhesive or the like.

Reference numerals 12A and 12B are correction coils for generating a correction magnetic field for correcting the earth magnetism.
A and 12B are respectively wound around the correction coil coil bobbin 11 several times in a circular shape at angles Θ _A and Θ _{B in} the horizontal direction with respect to the plane perpendicular to the tube axis.

Then, the respective correction coils 12A, 12
B has an inverting switch 1 similar to that shown in FIG.
3, the DC power supply 14, and the variable resistor 15 are arranged in series.

In the present embodiment, as shown in FIG. 7, when the screen 6B facing east is directed north, the geomagnetism from the left side to the right side of the drawing with respect to the screen 6B disappears, and the direction of the tube axis is increased. Geomagnetism is applied from the neck side toward the face to change the raster 10 and the landing as shown in FIGS. 7 and 10, but at this time, a magnetic field in the correction coil 12A is generated in the direction opposite to the geomagnetism in the tube axis direction. By passing a direct current in this manner, the geomagnetism in the tube axis direction is canceled and self-harm is generated from the left to the right toward the screen 6, and the magnetic field state is close to that when facing east. 2 and 3 are explanatory views of the state of the magnetic field when the screen faces north and south, respectively. Assuming that B _{N is} the geomagnetism in the northward and tube axial direction and B _A is the strength of the magnetic field generated when a direct current is applied to the correction coil 12A, each correction coil 1
2A, if the mounting angle of the 12B is Θ _A = Θ _B = Θ, the variable shown in Figure 5 as described above, to generate a strength B _A of the magnetic field so that B _A cosΘ + B _N = 0 in FIG. 2 By adjusting the current value with the resistor 15, the geomagnetism B _N in the tube axis direction can be canceled, and in addition, a magnetic field of B _A sin Θ from left to right toward the screen 6 can be generated.

When the correction coil 12B is also energized, the geomagnetism in the eastward direction is B _E , and the strength of the magnetic field generated in the correction coil 12B is B _B , B _A cos Θ + B _B cos Θ + B _N = 0 B _A sin Θ -B _B sinΘ = _{B E} become such magnetic field strength B _a, B _B become as correction coils 12A, be adjusted in each of the variable resistor 15 of 12B, and the same magnetic field as in the east The status can be obtained and the raster 10 and landing movements will not occur and the same normal raster 10 as shown in FIGS.
It can be corrected so that it becomes landing.

On the contrary, when the screen 6 is turned to the south, a DC current is applied to the correction coil 12B so as to generate a magnetic field in the direction opposite to the earth's magnetism. A magnetic field from left to right is generated, and a magnetic field close to that is obtained when facing east. When the geomagnetism facing south and B _S, by adjusting the variable resistor 15 shown in FIG. 5 so as to generate a _B B cosΘ + B _S = 0 and becomes such a magnetic field strength B _B as shown in FIG. 3, It is possible to cancel the geomagnetism B _S in the tube axis direction and further generate a magnetic field of B _B sin Θ from left to right toward the screen.

Furthermore when also energizing the correction coils _{12A, B B cosΘ + B A} cosΘ + B S = 0 B B sinΘ-B A sinΘ = B E become such magnetic field strength _B B, correction coils such that B _A By adjusting the variable resistors 15 of 12B and 12A respectively, it is possible to obtain the same magnetic field state in the east direction.
As in the case of facing north, the raster 10 and the landing do not move even in the southward direction, and the landing can be corrected to the same normal rastering 10 as shown in FIGS. 6 and 9.

In this way, each correction coil 12A,
By adjusting the amount of current by the reversing switch 13 and the variable resistor 15 of 12B, the movements of the raster 10 and the landing can be corrected at the same time and reliably, and it is possible to prevent the color from becoming murky and reliably display a high-quality color image. Various effects are exhibited.

Although the strength of the earth's magnetism varies depending on the place, it can be used at any place by adjusting the amount of current by the variable resistor 15.

In this embodiment, the correction coil coil bobbin 11 and the correction coils 12A and 12B are provided on the outer periphery of the front end enlarged portion 2A of the coil bobbin 2. However, the fixed position of the correction coil coil bobbin 11 is enlarged at the front end of the coil bobbin 2. It may be provided on the front end surface or the rear end surface of the portion 2A, or may be provided on the inner peripheral surface of the front end enlarged portion 2A.

On the other hand, The correction coils 12A and 12B may be provided in the rear end enlarged portion 2B of the coil bobbin 2. However, in this case, the spot of the electron beam 9 and the correction coil 12
Since the distance between A and 12B becomes long, the correction efficiency slightly decreases.

Further, in this embodiment, a pair of correction coils 12 is used.
Although A and 12 are provided at the same angle Θ with respect to the horizontal tube axis direction, the respective angles Θ _A and Θ _B are larger than 0 ° and 9 °.
Different values may be used as long as they are less than 0 °.

It is also possible to receive a plurality of correction coils, and when more than one correction coil is provided, it is not necessary for the additional portion to be a pair. It is also possible to provide it together with a correction coil which has been provided perpendicularly to a conventional tube axis.

[0031]

As described above in detail, according to the present invention, a pair of correction coils which are not parallel to the tube axis are provided on the front end side or the rear end side of the coil bobbin, and a direct current is applied to the coil bobbin so that the amount of change in the geomagnetism can be reduced. The magnetic field can be canceled, and the same magnetic field state as in the east direction can always be maintained. As a result, the movement of the raster and the landing due to the change of the earth's magnetism can be simultaneously and surely prevented, and a high-quality color image can be displayed.

[Brief description of drawings]

FIG. 1 is a plan view of a deflection yoke device for a color picture tube according to the present invention.

FIG. 2 is an explanatory diagram of a magnetic field when correction is performed by a correction coil facing north in the present invention.

FIG. 3 is an explanatory diagram of a magnetic field when correction is performed by a correction coil facing south in the present invention.

FIG. 4 is a plan view of a conventional deflection yoke device for a color picture tube.

FIG. 5 is a circuit configuration diagram including a correction coil of a deflection yoke device for a color picture tube.

FIG. 6 is an explanatory diagram of a screen showing a normal state of raster.

FIG. 7 is an explanatory diagram of a screen showing a raster state when the screen is facing north.

FIG. 8 is an explanatory diagram of a screen showing a raster state when the screen faces south.

9 is an enlarged explanatory view showing a state of a phosphor dot and a landing in a portion a of FIG.

FIG. 10 is an enlarged explanatory diagram showing a state of phosphor dots and landing in a portion b of FIG.

FIG. 11 is an enlarged explanatory view showing a state of phosphor dots and landing in the portion c in FIG.

12 is an explanatory diagram of a screen showing a state of a raster when correction is performed by a correction coil according to the related art in FIG. 7.

FIG. 13 is an explanatory diagram of a screen showing a state of a raster when correction is performed by a correction coil according to the related art with respect to FIG.

FIG. 14 is an explanatory diagram showing a state of landing and phosphor dots in a portion d of FIG.

FIG. 15 is an explanatory diagram showing a state of landing and phosphor dots in the portion e of FIG.

[Explanation of symbols]

 1 Color picture tube deflection yoke device 2 Coil bobbin 3 Core 4 Horizontal deflection coil 5 Vertical deflection coil 6 Color picture tube 6A Color picture tube neck 6B Color picture tube face screen 6C Color picture tube Phosphor screen 8 Phosphor dot 9 Electron beam 10 Raster 11 Correction Coil Coil Bobbin 12A, 12B Correction Coil 13 Inversion Switch 14 DC Power Supply 15 Variable Resistor

Claims (3)

[Claims] 1. A coil bobbin, a core provided on the coil bobbin, a horizontal deflection coil and a vertical deflection coil provided along the coil, and the coil bobbin is mounted on a neck portion of a color picture tube. In a deflection yoke device for a color picture tube, the coil bobbin is provided near a front end portion or a rear end side opening near a plane perpendicular to the tube axis of the picture tube for correcting the horizontal component of the geomagnetism and the influence of the tube axis direction. A deflection yoke device for a color picture tube, comprising: a pair of correction coils having a predetermined angle in the horizontal direction. 2. A deflection yoke device for a color picture tube, comprising a pair or more of the correction coils. 3. The deflection yoke device for a color picture tube according to claim 1, wherein the mounting angles of the pair of correction coils are the same.