JPH0414984A - Deflector for in-line type color cathode-ray tube - Google Patents

Abstract

PURPOSE:To correct bow pattern cased to upper and lower parts of the screen and mis-convergence by providing a correction circuit in which a slider of a 2nd 3-terminal variable resistor is connected to a contact of a couple of saddle type vertical deflection coil to the deflector. CONSTITUTION:In addition to a differential resistance circuit 27 connecting to a contact of a couple of saddle type vertical deflection coils 22a, 22b connected in series, a diode bridge circuit 30 is connected to the vertical deflection coils 22a, 22b in parallel connection with a couple of resistors 28a, 28b and a 2nd 3-terminal variable resistor 31 is connected across its output terminal and a slider is connected to the contact between the vertical deflection coils 22a, 22b in a correction circuit 32. Thus, bow pattern/mis-convergence unable to be corrected by the differential resistor circuit 27 are eliminated by the adjustment of the correction circuit 32.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention relates to an in-line color cathode ray tube deflection device, and is particularly suitable for a high-resolution color display tube. Regarding.

(Prior Art) In general, a color cathode ray tube has three electron beams (2B), (
2G) and (2R) are deflected by the horizontal and vertical deflection magnetic fields generated from each pair of horizontal and vertical deflection coils of the deflection yoke (3) mounted on the outside of the envelope, and A structure is formed in which a color image is displayed on the phosphor screen (5) by horizontally and vertically scanning the phosphor screen (5) through the formed shadow mask (4).

In such a color cathode ray tube, an electron gun (1
) consists of a center beam (2G) passing on the same horizontal plane and a pair of side beams (2B), (2R) - three electron beams arranged in a row (2B), (2G),
(2R) is emitted, and the three electron beams (2R) in this -row arrangement are emitted.
B), (2G).

(2R) is self-concentrated by a non-uniform magnetic field consisting of a binction type horizontal deflection magnetic field generated by a horizontal deflection coil and a barrel type vertical deflection magnetic field generated by a vertical deflection coil, without using an external circuit correction means. , a self-convergence type in-line color cathode ray tube that virtually matches the entire screen has been realized.

As a deflection yoke that generates the nonuniform magnetic field, there is a saddle-saddle type deflection yoke in which each pair of horizontal and vertical deflection coils is shaped like a saddle. Moreover, in this saddle-saddle type deflection yoke, in order to correct the vertical convergence deviation of the pair of side beams (2B) and (2R) at the top and bottom of the screen, as shown in Fig. 7, the pair of side beams (2B) and (2R) are connected in series. A pair of saddle-type vertical deflection coils (7a), (
A pair of resistors (8a) and (8b) are connected in parallel with 7b), and both ends of a three-terminal variable resistor (9) are connected between the resistors (8a) and (8b), and the sliding A pair of saddle-type vertical deflection coils (7a) connected in series with each other.
, (7b), and this three-terminal variable resistor (9) connects a pair of saddle-type vertical deflection coils (7a).
, <7b) is provided with a differential resistance circuit (10) for adjusting the balance of the deflection current flowing through the deflection currents.

When the differential resistance circuit (10) is provided in this way, the following effects can be obtained.

That is, as shown in FIG. 8(a), the pair of saddle-type vertical deflection coils (7a) and (7b) are symmetrical about the horizontal axis (X-axis) and the vertical axis (Y-axis). Barrel type vertical deflection magnetic field (12) with 3 electron beams (2B)
, (2G), (2R) occur in the array direction,
Correct the convergence shift. However, for example - pairs of saddle-type vertical deflection coils (7a), (7b)
When the deflection currents flowing in the side beams are different, as shown in (b), a vertical deflection magnetic field (12a) is created with the left and right symmetry broken, and the vertical force exerted by the pair of side beams (2B) and (2R) becomes The left and right sides are different, with Blue Wide or Red Wide at the top and bottom of the screen.
A convergence shift in the vertical direction called "Red Wi-de" occurs. In such a case, a pair of saddle-shaped vertical deflection coils (7a) are connected by a three-terminal variable resistor (9).
.

By adjusting the balance of the deflection current flowing in (7b), the symmetrical barrel-shaped vertical deflection magnetic field (12) shown in Fig. 8(a) can be obtained, thereby correcting the convergence shift (Wfde Narrow correction).

However, even if the differential resistance circuit (10) is arranged between the pair of saddle-type vertical deflection coils (7a) and (7b) as described above, the electron gun may be arranged at an angle due to manufacturing errors of color cathode ray tubes. , as shown in FIG. 8(c), the three electron beams (2
B) If the arrangement axis (13) of (2G), (2R) is tilted, even if the above correction (Wide Narrow correction) is performed by the differential resistance circuit (10), the 9th
As shown in the figure, there is a bow pattern (Bow pattern) at the top and bottom of the screen where the blue raster (14B) is on top and the red raster (141?) is on the bottom, or vice versa, with red raster on top and blue raster on bottom.
Pattern) misconvergence remains, making it difficult to perform the necessary correction.

(Problem to be Solved by the Invention) As described above, as a deflection device for an in-line color cathode ray tube, each pair generates a magnetic field that deflects three electron beams arranged in a row emitted from the electron gun in the horizontal and vertical directions. A saddle-saddle type deflection yoke is used, in which the horizontal and vertical deflection coils are each shaped like a saddle.Furthermore, in order to correct the convergence deviation of the pair of side beams at the top and bottom of the screen, a pair of vertical deflection coils connected in series is used. A differential resistor made by connecting a pair of resistors in parallel, connecting both ends of a 3-terminal variable resistor between the resistors, and connecting the slider to the contacts of a pair of saddle-type vertical deflection coils connected in series. There is one with an attached circuit.

However, even if a differential resistance circuit is arranged in a pair of saddle-type vertical deflection coils in this way, the electron gun is arranged at an angle due to manufacturing errors of color cathode ray tubes, and the electron gun is disposed at an angle relative to the vertical deflection magnetic field. If the electron beam array axis is tilted, bow pattern misconvergence remains at the top and bottom of the screen even if corrected by the differential resistance circuit, making it difficult to perform the required correction.

The present invention was made to solve the above problems, and it is an object of the present invention to construct an in-line color cathode ray tube deflection device that can correct the bow pattern misconvergence that occurs at the top and bottom of the screen, which cannot be corrected with a differential resistance circuit. purpose.

[Structure of the Invention] (Means for Solving the Problems) In an in-line color cathode ray tube deflection device, a magnetic field is generated to horizontally and vertically deflect a plurality of beams arranged in a row emitted from an electron gun of the color cathode ray tube. The deflection yoke is composed of a pair of saddle-type horizontal deflection coils and a pair of saddle-type vertical deflection coils, and a first resistor is connected between the deflection yoke and a pair of resistors connected in parallel to the pair of saddle-type vertical deflection coils. A differential resistance circuit is provided in which both ends of the three-terminal variable resistor are connected, and the slider of the first three-terminal variable resistor is connected to the contacts of the pair of saddle-type vertical deflection coils. Both ends of a second 3-terminal variable resistor are connected to the output terminals of a diode bridge circuit connected in parallel to the saddle-type vertical deflection filter, and this second
A correction circuit was provided in which the slider of the three-terminal variable resistor was connected to the contacts of the pair of saddle-type vertical deflection coils.

(Function) As described above, when a correction circuit is provided together with a differential resistance circuit for the pair of saddle-type vertical deflection coils of the deflection yoke, this correction circuit causes the vertical deflection current to flow to the pair of saddle-type vertical deflection coils. The balance can be reversely corrected when deflecting the upper part of the screen and when deflecting the lower part of the screen. In other words, the magnetic field distribution shape for deflecting to the upper and lower parts of the screen can be corrected to opposite patterns for upper and lower deflections. For example, at the upper and lower parts of the screen, one blue raster of a pair of side beams is on If a bow pattern or misconvergence occurs in which the other red raster is at the bottom, the other red beam will be deflected more strongly than one blue beam during upper deflection, and one blue beam will be deflected more strongly than the other red beam during lower deflection. can be strongly deflected to correct misconvergence in the bow pattern that cannot be corrected by adjusting the differential resistance circuit.

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 1 shows an in-line color cathode ray tube deflection device, which is an embodiment of the present invention. This deflection device consists of a separator (
A pair of saddle-shaped horizontal deflection coils (21a) arranged vertically symmetrically across the horizontal axis (X-axis) inside 20),
(21b) and a vertical axis (Y
A pair of saddle-shaped vertical deflection coils (22a), (22b) (only (22a) is shown) arranged symmetrically across the saddle-shaped vertical deflection coil (22a),
(22b) so as to cover the core (22b).
3) A saddle-saddle type deflection yoke is provided. each pair of deflection coils (21a);

(21b), (22a), and (22b) are connected in series.

As shown in Fig. 2, a pair of saddle-type vertical deflection coils (
A pair of resistors (25) are connected in parallel with 22a) and (22b).
a> , (25b) is connected, and this resistor (25a
).

(25b), both ends of the first 3-terminal variable resistor (26) are connected between the pair of saddle type vertical deflection coils (25b), and the slider of this 3-terminal variable resistor (26) is connected in series with the pair of saddle type vertical deflection coils (25b).
A differential resistance circuit (27) connected to the contacts 2a) and (22b) is attached.

Furthermore, in the deflection device of this example, the pair of saddle-type vertical deflection coils (22a), (
22b) and a pair of resistors (28a) connected in parallel with
, (28b), four diodes (29a)
Diode bridge circuit (30) consisting of ~(29d)
is connected, both ends of the 3-terminal variable resistor (31) of ji2 are connected to the output terminal of this diode bridge circuit (30), and the slider of this second 3-terminal variable resistor (31) is connected to the above-mentioned series A pair of connected saddle-shaped vertical deflection coils (
A correction circuit (32) connected to the contacts 22a) and (22b) is provided.

By the way, when the deflection device is configured as described above, the following effects can be obtained.

For example, suppose that three electron beams arranged in a row are emitted from an electron gun of a color cathode ray tube in an array shown in FIG. Furthermore, as shown in Figure 9, blue rasku (
Assume that a bow pattern misconception is occurring where 14B) is on the top and red raster (14R) is on the bottom. In addition, a pair of saddle-type vertical deflection coils (22a), (2
2b), it is assumed that one coil (22a) is placed on the right side and the other coil (22b) is placed on the left side as shown in FIG. In this case, the slider of the second three-terminal variable resistor (31) of the correction circuit (32) is moved in the direction of the arrow (34) shown in FIG. At this time, in the screen upper deflection period t1 of the vertical deflection current waveform (35) shown in FIG. 3, the vertical deflection current I or the arrow (36) shown in FIG.
The correction circuit (32) becomes an equivalent circuit (32a) shown in FIG. 4(a), and the left vertical deflection coil (2
2b), more current flows through the right vertical deflection coil (22a). As a result, a pair of side beams (2
B).

(2R), the magnetic flux density on the red beam (2R) side is larger than on the blue beam (2B) side, correcting the bow pattern misconvergence at the top of the screen.

Further, in the screen upper deflection period t2 of the vertical deflection current waveform (35) shown in FIG.
), and the correction circuit (32)
), the vertical deflection coil (22b) on the left side is larger than the vertical deflection coil (22a) on the right side.
More current flows, and the magnetic flux density on one blue beam (2B) side becomes larger than on the other red beam (2R> side), as shown in the vertical deflection magnetic field (38b) shown in FIG. 5(b). Correct the bow pattern φ misconvergence at the bottom of the screen.

In addition, in the above explanation, a case was described in which bow pattern misconvergence is corrected in which the blue raster is on top and the red raster is on the bottom at the top and bottom of the screen, but the deflection device in this example The bow pattern misconvergence below can be similarly corrected by moving the slider of the second three-terminal variable resistor of the correction circuit in the opposite direction.

[Effects of the Invention] For a saddle-type vertical deflection coil of a pair of saddle-saddle-type deflection yoke that generates a magnetic field that horizontally and vertically deflects a plurality of beams arranged in a row emitted from an electron gun of an in-line color cathode ray tube. , between the pair of saddle type vertical deflection coils and a pair of resistors connected in parallel.
A differential resistance circuit is installed in which both ends of a three-terminal variable resistor are connected, and its slider is connected to the contacts of a pair of saddle-type vertical deflection coils. If a correction circuit is provided in which both ends of a second three-terminal variable resistor are connected to the output terminals of the diode bridge circuit, and its sliders are connected to the contacts of a pair of saddle-type vertical deflection coils, the By adjusting the 3-terminal variable resistor (1), the convergence shift in the vertical direction at the top and bottom of the screen can be corrected, and the bow pattern misconvergence that cannot be corrected by this differential resistance circuit can be corrected by adjusting the second 3-terminal variable resistor of the correction circuit. By adjusting the variable resistor, it is possible to reversely correct and remove the balance of the currents flowing through the pair of saddle-type vertical deflection coils between when the screen is deflected at the top and when the screen is deflected at the bottom. Therefore, it is possible to obtain an in-line deflection device for color cathode ray tubes that has good convergence characteristics and can be applied to high-resolution color display tubes.

[Brief explanation of drawings]

1 to 5 are detailed explanatory diagrams of the present invention, and FIG. 1 is a perspective view showing the structure of a deflection yoke according to an embodiment thereof;
Fig. 2 is a circuit configuration diagram of an in-line type color cathode ray tube deflection device which is an embodiment of the invention, Fig. 3 is a waveform diagram of the vertical deflection current supplied to the vertical deflection coil, and Figs. 4 (a) and (b) are The equivalent circuit diagram of the first illustrated circuit when the screen is deflected at the top of the screen, and the equivalent circuit diagram of the first illustrated circuit when the screen is deflected at the bottom of the screen, respectively. A diagram of the vertical deflection magnetic field to correct and a diagram of the vertical deflection magnetic field to correct the misconvergence in the bow pattern at the bottom of the screen, Figure 6 is a diagram showing the configuration of a color cathode ray tube, Figure 7
The figure is a circuit configuration diagram showing the main parts of a conventional in-line color cathode ray tube deflection device, and FIGS. 8(a) to (C) are diagrams each showing the relationship between the three electron beams and the vertical deflection magnetic field.
(a) is a diagram showing the correct relationship, (b) is a diagram when the left and right balance of the vertical deflection magnetic field is disrupted and misconvergence occurs in a pair of side beams, and (C) is a diagram due to manufacturing errors of color cathode ray tubes. Figure 9 is a diagram showing the case where the electron gun is installed at an angle. Figure 9 shows the bow pattern misconvergence of a pair of side beams at the top and bottom of the screen that occurs when the electron gun is installed at an angle. It is. 2B, 2R... A pair of side beams, 2B... Center beam, 21a, 21b... A pair of saddle type horizontal deflection coils,
21a, 22b... a pair of saddle-shaped vertical deflection coils,
23... Core, 25a, 25b... Resistor, 26... First 3-terminal variable resistor, 27... Differential resistance circuit, 28a, 28b... Resistor, 29a-29d. ...Diode, 30...Diode bridge circuit, 31...Second 3-terminal variable resistor, 32...Correction circuit. Agent Patent Attorney Norihiro Ogo Figure 3 Figure 4 Figure 4 Figure 4

Claims (1)

[Claims] A pair of saddle-type horizontal deflection coils that generate a magnetic field that horizontally deflects a plurality of beams arranged in a row emitted from an electron gun of an in-line color cathode ray tube, and a magnetic field that deflects the plurality of beams vertically. a deflection yoke having a pair of saddle-type vertical deflection coils that generate a yoke; a pair of resistors connected in parallel with the pair of saddle-type vertical deflection coils; and a first deflection yoke having both ends connected between the pair of resistors. a differential resistance circuit comprising a three-terminal variable resistor, a slider of the first three-terminal variable resistor being connected to a contact point of the pair of saddle-type vertical deflection coils; It has a diode bridge circuit connected in parallel to the deflection coil and a second three-terminal variable resistor whose both ends are connected to the output terminal of the diode bridge circuit, and a slider of the second three-terminal variable resistor. is connected to the contacts of the pair of saddle-type vertical deflection coils, and is capable of reversely correcting the balance of the vertical deflection current flowing through the pair of saddle-type vertical deflection coils between when the screen is deflected at the top of the screen and when it is deflected at the bottom of the screen. An in-line color cathode ray tube deflection device characterized by comprising a circuit.