JPH0414391A - Deflector for in-line cathode ray tube - Google Patents

Abstract

PURPOSE:To optimize the coma aberration at the end of a horizontal axis of the screen and to eliminate green DO loop at the diagonal part of the screen by providing a saturable reactor and varying differentially currents flowing to two sets of sub coils synchronously with a vertical deflection current. CONSTITUTION:An impedance coil 36a, 36b of a saturable reactor 24 connects in series with a sub coil 21, 22 and a magnetic coil 39 is connected in parallel with a rectifier circuit 23 connected to a vertical deflection coil 28 wound on saturable cores 35a, 35b. Thus, the impedance of the coils 36a, 36b is varied synchronously with the vertical deflection current and the current flowing to the coils 21, 22 is varied differentially. then a change in pin cushion type magnetic field strength generated by the coils 21, 22 is strengthened in the same direction as a horizontal deflection magnetic field as the absolute value of the vertical deflection current increases, the coma aberration at the screen horizontal axis end is optimized and the green DO loop at the diagonal part of the screen is eliminated.

Description

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

(Prior Art) Generally, as shown in FIG. 6, a color cathode ray tube has three electron beams (2B) emitted from an electron gun (1),
(2G) and (2R) are deflected by the horizontal and vertical deflection magnetic fields of the deflection yoke (4) attached to the outside of the envelope (3), and the phosphor screen (6) is deflected horizontally through the shadow mask (5). , is formed in a structure that displays a color image on this phosphor screen (6) by vertical scanning.

In particular, for in-line color cathode ray tubes that emit three electron beams consisting of a center beam and a pair of side beams arranged in parallel on the same horizontal plane from an electron gun, the horizontal deflection magnetic field is pincushion-shaped and the vertical deflection magnetic field is barrel-shaped. A self-convergence type deflection yoke that generates a magnetic field is generally used.

When such a deflection yoke is combined with an in-line color cathode ray tube, there is no need for circuit correction means.
As shown in FIG. 7, the rasters (9B) and (9R) of the pair of side beams can be matched across the entire screen (8). However, the center beam raster (9G
) and a pair of side beam raster (9B), (
9R) is difficult to match, and comatic aberrations shown by HCR and VCR occur at the horizontal axis (X-axis) and vertical axis (y-axis) ends of the screen (8). This coma aberration is, for example, 14
For inch 90 degree deflection color picture tube, HCR is 0.5
! I11 is about 11 mm, VCR is about 1.0 to 2.0 mm, and in a normal color picture tube, a field controller made of a magnetic material that magnetically couples with the rear leakage magnetic field of the deflection yoke is installed on the beam emission end side of the electron gun. I installed it and corrected it to my satisfaction.

However, as shown in FIG. 8, when the HCR at the horizontal axis end of the screen (8) is optimally corrected, a pair of side beams (9B), (
9R), there is a green dow loop HGD in which the center beam raster (9G) is on the outside. Therefore, as a compromise, the actual correction is to set the HCR at the horizontal axis end to 0.1 to 0.2+n and set the HGD at the diagonal of the screen to about 0.1 to 0.2+n. ing.

Therefore, the misconvergence between the center beam raster (9G) and the pair of side beams raster (9B) and (9R) in this in-line color cathode ray tube is 062 to 0.4+nm, which is particularly useful for high-resolution color displays. The size is inappropriate for pipes, etc.

(Problems to be Solved by the Invention) As described above, a self-convergence type deflection yoke in which the horizontal deflection magnetic field is pincushion-shaped and the vertical deflection magnetic field is barrel-shaped, three electron beams are arranged in parallel on the same horizontal plane. When combined with an in-line color picture tube, it is possible to match the rasters of a pair of side beams, but it is difficult to match the rasters of the center beam and the rasters of a pair of side beams. Comatic aberrations HCR and VCR occur at the vertical axis ends. In order to correct this coma aberration, a typical color picture tube uses a field controller made of a magnetic material that magnetically couples with the rear leakage magnetic field of the deflection yoke.

However, when the HCR at the horizontal axis end of the screen is optimally corrected, there is a green dow loop HGD in the diagonal part of the screen where the raster of the center beam is outside of the raster of the pair of side beams. However, in the case of high-resolution color display tubes, it is not possible to correct the misconvergence to a satisfactory level.

This invention was made in view of the above problems, and
The object of the present invention is to configure a deflection device that does not have green dough loops in the diagonal portions of the screen when the HCR at the ends of the horizontal axis of the screen is optimized.

[Structure of the Invention] (Means for Solving the Problems) An in-line color cathode ray tube deflection including a deflection yoke having a horizontal deflection coil that generates a pincushion-shaped horizontal deflection magnetic field and a vertical deflection coil that generates a barrel-shaped vertical deflection magnetic field. In the device, two sets of pincushion-shaped magnetic fields are provided on the rear end side of the deflection yoke to generate pincushion-shaped magnetic fields in the same direction and in opposite directions in response to the pincushion-shaped horizontal deflection magnetic field by supplying a horizontal deflection current flowing through the horizontal deflection coil. a saturable core magnetically biased until just before saturation, and a pair of impedance coils connected in series to each of the two sets of subcoils and wound around the saturable core as a magnetic core, An impedance coil parallel circuit in which a pair of series circuits of the impedance coil and the sub-coil are connected in parallel, a rectifier circuit connected to the vertical deflection coil, and the vertical deflection coil wound around the saturable core and connected in parallel with the rectifier circuit. A saturable reactor was provided consisting of a magnetic coil connected to.

(Function) As described above, the impedance coil of the saturable reactor is connected in series to each of the two sets of subcoils, and the impedance coil parallel circuit, in which the series circuits are connected in parallel, is wound around the saturable core and connected to the vertical deflection coil. When connected to the magnetic coil connected to the vertical deflection coil in parallel with the connected rectifier circuit, the impedance of the impedance coil can be changed in synchronization with the absolute value of the vertical deflection current,
By changing the impedance of this impedance coil, it is possible to differentially change the current flowing through one subcoil and the current flowing through the other subcoil. As a result, a pincushion magnetic field in the same direction as the horizontal deflection magnetic field is generated in one subcoil, and a pincushion magnetic field in the opposite direction to the horizontal deflection magnetic field is generated in the other subcoil.

That is, one subcoil generates the main magnetic field, and the other subcoil generates the bias magnetic field. Changes in the strength of the pincushion magnetic field generated by these two sets of subcoils increase in the same direction as the horizontal deflection magnetic field as the absolute value of the vertical deflection current increases. , the horizontal deflection of the pair of side beams is stronger than the horizontal deflection of the center beam, making it possible to optimize the HCR at the ends of the horizontal axis of the screen and eliminate green doe loops at the diagonal portions of the screen.

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

FIG. 1 shows an in-line color picture tube deflection device, which is an embodiment of the present invention, and FIG. 2 shows a deflection yoke. This deflection device includes a deflection yoke (20), two sets of subcoils (21) and (22), a rectifier circuit (23), and a saturable reactor (24).

The deflection yoke (20) includes saddle-shaped horizontal deflection coils (26) arranged vertically symmetrically inside the mold (25).
and a toroidal vertical deflection coil (
28), and are configured to generate a pincushion-shaped horizontal deflection magnetic field and a barrel-shaped vertical deflection magnetic field, respectively.

The above two sets of subcoils (21) and (22) each have a pair of U-shaped cores (30) arranged symmetrically across the vertical axis (Y-axis) at the rear end of the deflection yoke (20). and,
A pair of series coils (31a), (31b) and (32a), (32
b), and is configured symmetrically. Each of the subcoils (21) and (22) is connected to a horizontal deflection coil (26) via an impedance coil of a saturable reactor (24), which will be described later.
By supplying the horizontal deflection current flowing through the deflection yoke (20
), one subcoil (21) generates a pincushion-shaped magnetic field in the same direction as the pincushion-shaped horizontal deflection magnetic field of the horizontal deflection coil (26), and the other subcoil (22) generates a pincushion-shaped horizontal magnetic field in the same direction as the pincushion-shaped horizontal deflection magnetic field of the horizontal deflection coil (26). It is designed to generate a pincushion-shaped magnetic field in the direction.

The saturable reactor (24) also includes a pair of cylindrical saturable cores (35a) and (35b), and one subcoil (21) of the two sets of subcoils (21) and (22). One saturable core (35
Impedance coil (3) wound with a) as a magnetic core
6a) and the other subcoil 22),
Similarly, it has an impedance coil (3Bb) wound around the other saturable core (35b) as a magnetic core. These impedance coils (36a) and (38b) are connected in parallel, and two sets of subcoils (21) and (2
2) Current flowing through I21. In order to reduce changes in inductance due to the influence of I22, it is composed of two series-connected coils (37a), (37b) and (37c), (37d) each having opposite polarity. In addition, each saturable core (35a).

(35b) has magnets (38) arranged at both ends so as to operate in a non-linear region, and this magnet (
38) is configured to be magnetically biased.

Furthermore, this saturable reactor (24) has a magnetic coil (39) wound around the saturable cores (35a) and (35b). This magnetic coil (39) includes a rectifier circuit (23) that connects four rectifying elements (40) in a bridge shape to full-wave rectify the sawtooth vertical deflection current flowing through the vertical deflection coil (28), and a magnetic coil. (38) is connected in parallel to a variable resistor (41) that adjusts the current flowing through it, and is connected to the vertical deflection coil (28) via the rectifier circuit (23) and the variable resistor (40).

Next, the operation of this deflection device will be explained.

Assuming that the electron beam is to be deflected upward, when a vertical deflection current IV in the direction of the arrow (42) flows through the vertical deflection coil (28), the rectifier circuit (23) flows through the magnetic coil (39).
A vertical deflection current flows which is full-wave rectified by and adjusted by a variable resistor (41). As a result, the saturable core (3
5a), magnetic flux φ in the direction of arrow (43) in (35b)
■ occurs, and at the same time each impedance coil (36a), (38b) connected to the horizontal deflection coil (26)
If magnetic flux φL in the directions of arrows (44a) and (44b) is generated, the magnetic flux in the saturable core (35a) of the impedance coil (36a) is φV+φL The saturable core (35b) of the impedance coil (36b)
) is φV−φL, and the inductance of the impedance coil (36a) is relatively small, whereas the inductance of the impedance coil (36a) is relatively small.
The inductance of 6b) becomes large.

Also, when deflecting the electron beam downward, a vertical deflection current that is full-wave rectified by the rectifier circuit (23) and adjusted by the variable resistor (41) flows through the magnetic coil (39), and each impedance coil (36a ), (36b)
The inductance changes in the same way as in the case of upward deflection.

Therefore, according to this deflection device, two sets of subcoils (21), (2
2) Current flowing through 121. I22 is shown in Figure 4 (
Curves (46a) and (48b) shown in a) and (b)
become that way. As a result, the electron beam (2B), (
2G).

(2R) to the left of the screen, the pincushion-shaped magnetic field (47a) shown in FIG. 3(a) is applied to one subcoil (21), and the same (b
) A pincushion-shaped magnetic field (47b) is generated.

Furthermore, when the electron beam is deflected to the right of the screen, a pincushion-shaped magnetic field is generated in the opposite direction to that for the leftward deflection, and a synthetic pincushion-shaped magnetic field is generated by the subcoils (21) and (22) of 2a. The strength of the magnetic field Bab is
As shown in Figure 5, the pincushion-shaped magnetic field is strong at the top and bottom edges of the screen and becomes zero at the center of the screen, and the direction of the pincushion-shaped horizontal deflection magnetic field is the same as that of the horizontal deflection magnetic field generated by the horizontal deflection coil (26). Become. Therefore, when the electron beam is deflected to the diagonal part of the screen, two sets of subcoils (21) and (22
), the strength Bab of the pincushion magnetic field obtained by
It is possible to eliminate green dow loops that occur in the diagonal portions of the screen when optimally correcting CR.

That is, in the deflection device of this example, two sets of subcoils (21) and (22) are synchronized with the scanning period in the vertical direction of the screen.
It is possible to dynamically change the strength Bab of the pincushion magnetic field obtained by the HCI? at the end of the horizontal axis of the screen. It is possible to optimally correct the green dot loop in the diagonal portion of the screen. Moreover, the operating point of the saturable reactor (24) can be easily adjusted by the variable resistor (41) connected in parallel with the magnetic coil (38), and the green dough loop can be easily corrected.

[Effects of the Invention] A horizontal deflection current flowing through the horizontal deflection coil is supplied to the rear end side of a deflection yoke that has a horizontal deflection coil that generates a pincushion-shaped horizontal deflection magnetic field and a vertical deflection coil that generates a barrel-shaped vertical deflection magnetic field. Accordingly, two sets of subcoils that generate pincushion-shaped magnetic fields in the same and opposite directions in response to the above pincushion-shaped horizontal deflection magnetic field are arranged, and a saturable core that is magnetically biased until just before saturation and the above two sets of subcoils are arranged. a pair of impedance coils each connected in series and wound around the saturable core as a magnetic core; an impedance coil parallel circuit in which a pair of series circuits of the impedance coil and the sub-coil are connected in parallel; By providing a saturable reactor consisting of a rectifier circuit connected to the deflection coil and a magnetic coil wound around the saturable core and connected to the vertical deflection coil in parallel with the rectifier circuit, synchronization is achieved with the absolute value of the vertical deflection current. The impedance of a pair of impedance coils can be changed by changing the impedance, and by changing the impedance, the current flowing through one subcoil and the current flowing through the other subcoil can be differentially changed. It is possible to generate a pincushion magnetic field in the same direction as the deflection magnetic field, and a pincushion magnetic field in the opposite direction to the horizontal deflection magnetic field in the other subcoil. In other words, one subcoil generates the main magnetic field, the other subcoil generates the bias magnetic field, and the change in pincushion magnetic field strength generated by these two sets of subcoils increases as the absolute value of the vertical deflection current increases. Since the horizontal deflection magnetic field is strengthened in the same direction as the horizontal deflection magnetic field, the horizontal deflection of the pair of side beams becomes stronger with respect to the horizontal deflection of the center beam as you move from the center of the screen to the periphery in the vertical direction.
In addition to optimizing CR, it is possible to eliminate green dow loops at the diagonal portion of the screen, and it is possible to realize an in-line color picture tube having good convergence characteristics.

[Brief explanation of the drawing]

1 to 5 are detailed explanatory diagrams of the present invention, FIG. 1 is a circuit diagram showing the configuration of an in-line type color picture tube deflection device which is an embodiment thereof, and FIG. 2 is a configuration of its deflection yoke. Figures 3 (a) and (b) are diagrams showing the relationship between the currents flowing through the two subcoils, and Figures 4 (a) and (b) are the pins generated by the two subcoils. A diagram showing the direction of the cushion-shaped magnetic field, Figure 5 is 2
Figure 6 is a diagram showing the strength of the pincushion magnetic field obtained by combining a set of subcoils, Figure 6 is a diagram showing the configuration of a color picture tube, Figure 7 is an illustration of coma aberration that occurs in an in-line color picture tube, FIG. 8 is a diagram showing the relationship between the HCR of coma aberration and the green doe loop in an in-line color picture tube. 20... Deflection yoke, 21... Sub coil, 22...
... Subcoil, 23... Rectifier circuit, 24...
Saturable reactor 26... horizontal deflection coil, 28...
・Vertical deflection coil, 30...core, 31a, 31b
... a pair of series coils, 32a, 32b... a pair of series coils, 35a, 35b... a pair of saturable cores, 36a, 36b... a pair of impedance coils,
37a-37d...Coil, 3B...Magnet,
39... Magnetic coil, 40... Rectifying element, 41
...Variable resistance. Agent Patent Attorney Nori Ogo Figure 2 Figure Figure Figure Figure Figure

Claims (1)

[Scope of Claims] A deflection yoke including a horizontal deflection coil that generates a pincushion-shaped horizontal deflection magnetic field and a vertical deflection coil that generates a barrel-shaped vertical deflection magnetic field; Two sets of sub-coils that generate pincushion-shaped magnetic fields in the same and opposite directions as the pincushion-shaped horizontal deflection magnetic field by supplying horizontal deflection current flowing through the deflection coils, a saturable core that is magnetically biased until just before saturation, and the above-mentioned 2 sub-coils. an impedance coil parallel circuit comprising a pair of impedance coils connected in series to each of the subcoils of the set and wound around the saturable core as a magnetic core, and a pair of series circuits of the impedance coil and the subcoil connected in parallel; , a rectifier circuit connected to the vertical deflection coil, and a magnetic coil wound around the saturable core and connected to the vertical deflection coil in parallel with the rectifier circuit, the rectifier circuit rectifying the magnetic coil. The vertical deflection current supplied to the saturable core generates magnetic fluxes with opposite phases in the winding portion of one impedance coil and the winding portion of the other impedance coil of the saturable core. and a saturable reactor that differentially changes the current flowing through the subcoil in synchronization with the vertical deflection current.