JPH0775151B2 - CRT display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CRT (color cathode ray tube) display device having an in-line type electron gun, and more particularly to improvement of a deflection yoke.

[Conventional technology]

Generally, in a CRT display device having an in-line type electron gun, as a deflection yoke for deflecting an electron beam, a deflection magnetic field generated by a horizontal deflection coil is a pin magnetic field, and a deflection magnetic field generated by a vertical deflection coil is a barrel magnetic field. The self-convergence type is used. According to the deflection yoke having such a structure, the horizontal misconvergence between the side beams on the horizontal axis is corrected by the pin magnetic field of the horizontal deflection coil, and the barrel magnetic field of the vertical deflection coil is used on the vertical axis. The horizontal misconvergence between the two side beams of is corrected so that the misconvergence of both side beams on the horizontal and vertical axes of the screen can be made almost zero, but in practice, , CRT
The misconvergence cannot be reduced to zero due to the above structure and the structure of the deflection yoke itself, and various patterns of misconvergence occur.

FIG. 6 shows an example of a misconvergence pattern when a deflection yoke having a uniform magnetic field is used for both the horizontal deflection coil and the vertical deflection coil, and FIG. 7 shows a deflection yoke having only the magnetic field of the horizontal deflection coil as a pin field. FIG. 8 shows an example of a misconvergence pattern in the case of using, and FIG. 8 shows a misconvergence pattern in the case of using a deflection yoke in which the magnetic field of the vertical deflection coil is a barrel magnetic field.
An example is shown. In these figures, 8 is a blue pattern, 9 is a green pattern, and 10 is a red pattern, which are formed on the screen P by rastering by the electron beams of blue, green and red.

As described above, the magnetic field of the horizontal deflection coil is a pin magnetic field,
Moreover, by making the magnetic field of the vertical deflection coil a barrel magnetic field, the misconvergence of both side beams on the horizontal axis XX and the vertical axis YY can be corrected, but as shown in FIG. In the corner portion of the screen P, a misconvergence amount of PQv remains in the vertical direction on both side beams. This misconvergence amount PQv
Has a property of varying depending on the size of the cathode ray tube, the curvature of the front panel of the cathode ray tube, the deflection angle, and the like. Further, in order to reduce the misconvergence amount PQv as described above, it has been conventionally attempted to change the winding distribution of each deflection coil.However, for example, if the winding distribution of the horizontal deflection coil is changed, If horizontal misconvergence Xh of both side beams occurs on XX, and if the winding distribution of the vertical deflection coil is changed, the vertical axis Y
The total amount of misconvergence T of Xh-Yh + PQv cannot be decreased due to a change in winding distribution such as a horizontal misconvergence Yh of both side beams on -Y.

For this reason, in the conventional deflection yoke, a means for compromising the convergence accuracy of the entire screen by allocating the total amount T of misconvergence to the respective misconvergence PQv, Xh, Yh has been adopted. .

As another means, for example, as disclosed in Japanese Patent Laid-Open No. 58-14453, a misconvergence pattern as shown in FIG. 8 is created by adjusting the winding distribution of the deflection coil. The one in which the misconvergence PQv remaining at the corner of P is corrected by a coil connected in series with a horizontal deflection coil and to which a magnetic bias is applied, and JP-A-61-142887 are disclosed. As described above, a misconvergence pattern as shown in FIG. 9 is created by adjusting the winding distribution of each deflection coil, and the misconvergence Yh remaining on the vertical axis YY of the screen P is corrected by the parabolic correction. There is known a configuration in which correction is performed by a correction coil to which a signal is input.

[Problems to be Solved by the Invention]

Among the conventional deflection yokes configured as described above, the one that distributes the total amount of misconvergence to ensure the convergence accuracy in a compromised manner provides satisfactory convergence characteristics and resolution in display devices with high resolution requirements. Has the drawback that it cannot be obtained, and
If one misconvergence pattern is positively created and the remaining misconvergence is corrected by a special coil for correction, the circuit configuration becomes complicated, and the deflection yokes vary in performance as the cost increases. There was a problem that was likely to occur.

The present invention has been made to solve the above-mentioned problems, and has a deflection yoke capable of correcting the total amount of misconvergence to zero with a simple structure and significantly improving the convergence accuracy of the entire screen. The purpose is to obtain a CRT display device.

[Means for Solving the Problems]

The CRT display device according to the present invention is a self-convergence type in which the basic magnetic field distribution of the deflection yoke main body is such that the horizontal deflection magnetic field is a pin magnetic field and the vertical deflection magnetic field is a barrel magnetic field.
In a CRT display device, a U-shaped magnetic body is formed at the rear left and right positions of a deflection yoke that electromagnetically deflects an electron beam, a horizontal deflection auxiliary coil wound around the magnetic body, and a magnetic body is magnetically attached to the magnetic body. A bonded magnet is provided, and the magnetic flux of the horizontal deflection auxiliary coil and the magnetic flux of the magnet are used to saturate the coiled portion of the magnetic body. (3) The description in paragraph 7, line 5 to page 8, line 1 of the same paragraph is corrected as follows.

"A magnetic coil is wound by the magnetic flux of the horizontal deflection auxiliary coil wound around the U-shaped magnetic body and the magnetic flux of the magnet magnetically bonded to the magnetic body according to the present invention. The portion in which the electron beam is saturated is made saturable in the horizontal deflection cycle, and the magnetic flux changing in the horizontal deflection cycle corrects the misconvergence Xh in the peripheral portion of the horizontal deflection of the electron beam.

[Action]

According to the present invention, in the two horizontal deflection auxiliary coils provided at the left and right positions behind the deflection yoke, the amount of magnetic flux generated from the left and right auxiliary coils is changed differentially in the horizontal deflection cycle, so that the auxiliary coil The magnetic field can be applied to the three electron beams in an unbalanced manner, and the interval between the electron beams can be changed in the horizontal deflection cycle.

In the method of operatively changing the amount of magnetic flux generated from the left and right auxiliary coils in the horizontal deflection cycle, the auxiliary coil is a supersaturated reactor, and the above operation can be realized with a simple structure. By using this method, the misconvergence at the corners of the screen is adjusted to zero by adjusting the winding distribution of the horizontal deflection coil, and the misconvergence on the horizontal axes of the remaining side beams is provided behind the deflection yoke. By correcting with the auxiliary coil, it is possible to eliminate the Misson-vergence of the entire screen.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a side view of the vicinity of a deflection yoke of a CRT display according to the present invention, and FIG. 2 is a configuration diagram of an Xh correction coil portion, in which 1 is a main body core and 2 is a vertical deflection coil wound in a toroidal shape. Reference numeral 4 denotes an in-line array of blue (B), green (G), and red (R) electron beams arranged in the neck portion 13 of the cathode ray tube (not shown). Reference numeral 5 is an Xh correction coil, 11 is a U-shaped magnetic body, around which a horizontal deflection auxiliary coil 12 through which a horizontal deflection current or a part thereof flows is wound. Reference numeral 7 is a magnet for making the coil 12 supersaturated.

Next, the operation of the above configuration will be described. FIG. 3 shows the horizontal mis-convergence Yh of both side beams on the vertical axis Y-Y and the vertical direction of both side beams at the corners of the screen P by adjusting the winding distribution of the horizontal deflection coil and the vertical deflection coil. Miss Convergence
The PQv is set to zero, and the misconvergence pattern before correction in which only the horizontal misconvergence Hh of both side beams on the horizontal axis XX is left is shown.

To correct this misconvergence pattern,
Red (R) as the horizontal deflection of the electron beam increases
It is necessary to widen the distance between the two electron beams of blue and blue (B). The Xh correction coil using the saturable reactor according to the present invention performs this function.

FIG. 4 shows the operation of the Xh correction coil. A current in synchronization with the horizontal deflection current flows through the horizontal deflection auxiliary coil 12. This may be the horizontal deflection current itself or a part thereof. As a result, a magnetic flux 15 is generated in the U-shaped magnetic body 11. A magnetic flux 16 from the magnet 7 acts on the U-shaped magnetic body 11, and the portion around which the auxiliary coil 12 is wound is in a saturable state. In addition, the direction of the magnetic flux passing through the saturable parts on the left and right is that the magnetic flux by the magnet and the magnetic flux by the coil are the same in one direction, and the other is in the opposite direction. That is, there is a difference in the amount of magnetic flux generated. As a result, the amount of magnetic flux generated from the U-shaped magnetic body 11 and acting on the electron beam is unbalanced on the left and right, and as shown in the figure, the electron beam on the side with a large amount of generated magnetic flux is large. Biased. By this action, the distance between the blue (B) and red (R) side beams is widened, and the misconvergence Xh on the screen is corrected.

Of course, when the horizontal deflection direction is reversed, the current flowing through the auxiliary coil 12 is reversed, so that the actions of the left and right coils are reversed as shown in FIG. 5, but the misconvergence Xh is similarly corrected.

〔The invention's effect〕

As described above, according to the present invention, by using the basic magnetic field distribution of the self-convergence method in which the horizontal coil is the pin magnetic field and the vertical coil is the barrel magnetic field, the horizontal deflection assist wound around the U-shaped magnetic body is used. Since the magnetic flux of the coil and the magnetic flux of the magnet magnetically bonded to the U-shaped magnetic body are configured to make the coiled portion of the magnetic body saturable, The structure of the means for obtaining the desired convergence is simple, and the operation of obtaining the desired convergence is effectively and efficiently.

[Brief description of drawings]

FIG. 1 is a side view of a deflection yoke of a CRT display device according to an embodiment of the present invention, FIG. 2 is a configuration diagram of an Xh correction coil, FIG. 3 is a misconvergence pattern in which only Xh is left, and FIG. 4 is Xh. FIG. 5 is an operation explanatory view of the Xh correction action by the correction coil, FIG. 5 is an operation explanatory view when the horizontal deflection direction in FIG. 4 is reversed, and FIG. 6 is a misconvergence pattern when a deflection yoke having a uniform magnetic field is used, FIG. 7 is a misconvergence pattern in the case of a deflection yoke in which the magnetic field of the horizontal deflection coil is a pin field, FIG. 8 is a misconvergence pattern in the case of a deflection yoke in which the magnetic field of the vertical deflection coil is a barrel magnetic field, and FIG. This is a misconvergence pattern in which the horizontal misconvergence of both side beams remains on the vertical axis. 1 ... Main body core, 2 ... vertical deflection coil, 5 ... Xh correction coil, 7 ... magnet, 8,9,10 ... blue, green, red pattern, 11 ... magnetic material, 12 ... horizontal Deflection auxiliary coil. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a CRT display device of a self-conversion system in which a basic magnetic field distribution of a deflection yoke main body is a pin magnetic field for a horizontal deflection magnetic field and a barrel magnetic field for a vertical deflection magnetic field, rear left and right of a deflection yoke for electromagnetically deflecting an electron beam. A magnetic body having a U-shape at each position, a horizontal deflection auxiliary coil wound around the magnetic body, and a magnet magnetically bonded to the magnetic body are provided, and a magnetic flux of the horizontal deflection auxiliary coil is provided. A CRT display device, characterized in that a portion around which the coil of the magnetic material is wound is made into a saturable state by the magnetic flux of the magnet.