JPH0766757B2 - Deflection yoke device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a deflection yoke device mounted on a cathode ray tube (hereinafter, referred to as CRT) having three electron guns in an in-line arrangement and used. In particular, it relates to a convergence correction device.

[Prior Art] In a deflection yoke device used in a CRT having three electron guns in an in-line arrangement, a deflection yoke generally composed of a horizontal deflection coil having a pin magnetic field component and a vertical deflection coil having a barrel magnetic field component. Is used.

In this case, due to the misconvergence of both side beams and the center beam due to the barrel-type vertical deflection magnetic field, as shown in FIG. 9, raster coma aberration (Q) appears at the upper and lower parts of the screen (F). Occurs and requires some corrective means.

Also, between both side beams, for example, the screen (F)
When it is averaged and shown in the first quadrant, which is equally divided into 1/4, as shown in FIG. 8, the amount of error indicated by Yh, PQv, and Xh is incorrect at the top, corner, and left and right parts of the screen (F). A convergence pattern occurs. These misconvergence Xh, Yh, PQ
In v, the value of Xh-Yh + PQv is usually called the trilemma.

This trilemma is uniquely determined by the structure of the deflection yoke, and in many cases, it does not completely become zero, and a trilemma residue is generated and various misconvergences occur. Therefore, a means for correcting the trilemma, which is a component of misconvergence, is also required.

Conventionally, there is a convergence correction device capable of simultaneously correcting the coma aberration and the trilemma as described above.
It is disclosed in Japanese Patent Publication No. 61-253750.

As shown in FIG. 12, the conventional convergence correction device disclosed in the above publication has a CR (1) behind a deflection yoke (15) formed by winding a vertical deflection coil (5) around a core (1).
As shown in FIG. 13, a pair of left and right E-shaped magnetic bodies (11) and (12) are provided on both sides of the T-link part (2).
Correction coils (37) and (38) are respectively wound around the intermediate portion and both end portions of the character-shaped magnetic bodies (11) and (12) that face each other in the horizontal direction, and vertical deflection current is applied to these correction coils (37) and (38). And a barrel-shaped magnetic field (39) in the neck portion (2) in the direction opposite to the direction of the main vertical deflection magnetic field by the intermediate winding, and in the same direction as the main vertical deflection magnetic field by the both end windings. It is configured to generate an oriented pink twitch type magnetic field (40).

Next, the operation of the above configuration will be described.

When a vertical deflection current is applied to the correction coils (37) and (38), the barrel-shaped magnetic field (3
9) and the pink twitch type magnetic field (40) generated by the windings at both ends have a difference in the deflection force of the vertical components of the center beam (G) and the side beams (B) and (R). The aberration is corrected, and the trilemma is corrected by arbitrarily adjusting the ratio of the two magnetic fields (39) and (40). That is, when the action of combining the two magnetic fields (39) and (40) deflects the beams (B), (G), and (R) in the same direction as the vertical deflection direction, the trilemma is corrected in the positive direction. , And vice versa, the trilemma is corrected in the negative direction.

[Problems to be Solved by the Invention] Since the conventional deflection yoke device is configured as described above, it is possible to perform coma aberration correction and trilemma correction, but in that case, the coma aberration correction amount and the trilemma correction are performed. When setting the amount arbitrarily, it is necessary to adjust the number of turns of the correction coil and the shape of the magnetic material, and in view of the trilemma correction principle, the upper and lower parts of the screen have a correlation with the trilemma correction amount at the time of trilemma correction. There was a problem such as the change in the raster distortion of.

In addition, the actual coma aberration is often non-linear as shown in FIG. 10, and since a vertical deflection sawtooth wave current is passed through the correction coil, the above-described correction device uses the vertical intermediate portion when correcting the coma aberration. There was a problem such as overcorrection.

The present invention has been made to solve the above problems, and simultaneously corrects non-linear coma aberration and trilemma, which is a component of misconvergence, without changing the upper and lower raster distortions. It is an object to provide a deflection yoke device that can be achieved.

[Means for Solving the Problems] In a deflection yoke device according to the present invention, a pair of left and right central correction coils each having a pole on a horizontal axis of an in-line arrangement are provided at a rear portion of the deflection yoke, and above the horizontal axis. A correction coil device including an upper side correction coil having a pole at each diagonal portion and a lower side correction coil having a pole at each lower diagonal portion of the horizontal axis is arranged, and an upper side correction coil and a lower side portion are provided. First and second serially connected correction coils that form an upper side series connected body and a lower side series connected body
Third diode connected in anti-parallel relationship with the above diode and connected in parallel with the parallel connection body of the upper side series connection body and the lower side series connection body; and the first and second diodes. And an impedance element that applies a voltage to the third and fourth diodes, and is configured to supply a vertical deflection current to the central correction coil and the parallel connection body. It is characterized by

[Operation] According to the present invention, by supplying a predetermined correction current to each coil of the correction coil device, the coma aberration is corrected into a linear shape by the magnetic field generated by the central correction coil, and the upper side is corrected. The coma aberration is corrected non-linearly by the magnetic field generated by the partial correction coil and the magnetic field generated by the lower side correction coil, and the misconvergence at the upper part of the screen is also corrected non-linearly. Therefore, as a combination of both magnetic fields, the coma aberration and the trilemma which is a component of misconvergence can be corrected with almost no change in the upper and lower raster distortion.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view showing the configuration of a correction coil device in a deflection yoke device according to an embodiment of the present invention. In FIG. 1, (11) and (12) are a pair of left and right E-shaped magnetic bodies,
It is located on both sides of the CRT network (2). (31),
Reference numeral (32) is a pair of left and right central correction coils, each having a pole on the horizontal axis (h) of the in-line arrangement.

Reference numerals (33) and (34) denote upper side correction coils, each of which has a pole at an upper diagonal portion of the horizontal axis (h). (3
5) and (36) are lower side correction coils, which are the horizontal axis (h) above.
Has a pole in the lower diagonal part of each.

The central correction coils (31), (32), the upper side correction coils (33), (34) and the lower side correction coils (35),
The correction coil device is constituted by (36).

FIG. 2 is a circuit diagram showing a connection state of the correction coil device in the deflection yoke device. In FIG. 2, (4) is a vertical deflection circuit, and vertical deflection coils (5) are connected in series, The pair of left and right center correction coils (31) and (32) are connected in series to the vertical deflection coil (5). (61) is a variable resistor, and the central correction coil (3
It is connected so that the currents flowing in 1) and (32) are differentially adjusted.

The upper side correction coils (33) and (34) and the lower side correction coils (35) and (36) are connected in series, and the vertical deflection coil (5) is in parallel with each other.
Is connected to the upper side correction coils (33) and (34) in series with a variable resistor (63) and two diodes (D3) and (D4), and the lower side correction coils (35). , (36)
A variable resistor (62) and two diodes (D1) and (D2) are connected in series with each other.

(71) and (72) are resistors as impedance elements that apply voltage to the diodes (D ₁ ) and (D ₂ ), respectively, and the vertical deflection current is passed through the resistor (71) and the lower side of the resistor (72). The local correction coil current is connected so as to be energized.

Next, the operation of the above configuration will be described with reference to the current waveform diagram of FIG.

From the vertical deflection circuit (4) to the vertical deflection coil (5),
When the vertical deflection current Iv as shown in FIG. 3A flows, the central correction coils (31) and (32) connected in series to the vertical deflection coil (5) are connected to the central correction coils (31) and (32) as shown in FIG. 3B. A sawtooth current Ic as shown flows. At this time, the variable resistance (61) differentially adjusts the current flowing through the central correction coils (31), (32), and the vertical deflection current Iv is passed through the resistance (71).

Now, when the vertical deflection current Iv is positive, the correction current Is does not flow through the upper side correction coils (33) and (34) due to the diode (D3). Assuming that the resistance value of the resistor (71) is R1, if the value of Iv × R1 becomes larger than the forward voltage of the diode (D1), the diode (D1) becomes conductive and the diode (D1) → lower side correction coil (35 ), (36) → Variable resistance (62) → Resistance (72)
The lower side correction coil current Is flows through the path of.

Since diodes (D2) and (D4) are connected to the resistor (72), if the resistance value of the resistor (72) is R2, then Is
When the value of × R2 becomes larger than the forward voltage of the diode (D2), the diode (D2) becomes conductive.

As described above, the lower side correction coil current Is is shaped like a parabola as shown in FIG. 3 (c). Incidentally, FIG. 3 (c) in the t1, t2 the diode (D1), adopted (D2) indicates the time at which the conduction, change in t ₂ are two diodes (D ₁₎ (D ₂₎ This is the result of what we did.

Even when the vertical deflection current Iv is negative, the upper side correction coil current Iw is shaped like a parabola as shown in FIG. 3 (d) in the same manner as above. T3 and t4 shown in FIG. 3 (d)
Indicates the time when the diodes (D3) and (D4) are conducting. Further, the correction coil currents Is and Iw can be arbitrarily adjusted by the variable resistors (62) and (63).

FIG. 9 shows an example of the misconvergence pattern before being corrected by the deflection yoke device. The coma aberration Q and the misconvergence Yh shown in FIG. 9 are generally from the screen center O in the vertical direction. It has a non-linear characteristic as shown in FIGS. 10 and 11 with respect to distance.

Next, the operation principle for correcting the non-linear coma aberration Q and the misconvergence Yh as shown in FIG. 9 by the deflection yoke device having the above configuration will be described.

First, the case where the screen is deflected upward will be described.

The central correction coils (31) and (32) are set so as to generate a magnetic field in the direction indicated by F1 in FIG. 4 when being deflected upward in the screen. As a result, the three beams B, G, R receive the deflection forces fb, fg, fr in the directions opposite to the vertical deflection, as indicated by the arrows. The deflection force is the center beam G
The deflection force fb, fr of both side beams B, R compared to the deflection force fg of
Is stronger, and thereby the coma aberration Q is corrected. The correction amount of the coma aberration Q at this time is as follows.
It is the sawtooth wave current Ic as shown in FIG. 3 (b) flowing in 1) and (32).

The lower side correction coils (35) and (36) are F2 in FIG.
It is set to generate a magnetic field in the direction indicated by. As a result, the center beam G is deflected in the same direction as the vertical deflection.
Upon receiving fg1, both side beams B and R receive deflection forces fb1 and fr1 having horizontal components, respectively. Therefore, coma aberration Q
Is corrected, and misconvergence Yh is also corrected.
The correction amount increases in a parabola shape as it goes to the upper end of the screen by the lower side correction coil current Is as shown in FIG. 3 (c).

At this time, no current flows through the upper side correction coils (33) and (34). That is, the coma aberration Q and misconvergence Yh in the upper half of the screen are the center correction coil (31),
It is corrected only by (32) and the lower side correction coils (35), (36).

When the image is deflected downward in the screen, the lower side correction coils (35) and (36) become non-conducting contrary to the above upward deflection, and the central correction coils (31) and (32). And the upper side correction coils (33) and (34) are used to correct the same operating principle as above.

As a result of the above operation, the correction characteristic of coma aberration as shown in FIG. 6 and the Yh correction characteristic as shown in FIG. 7 are obtained, which coincide with the characteristics of FIG. 10 and FIG. 11, respectively. Good convergence characteristics can be obtained over the entire screen.

6 and 7, A is a correction effect area due to the magnetic field generated by the central correction coils (31) and (32), and B is generated by the lower correction coils (35) and (36). The correction effect area by the magnetic field generated by C, C is the correction effect area by the magnetic field generated by the upper side correction coils (33), (34).

Further, as is apparent from the above operation principle, the variable resistors (62) and (63) can independently adjust and correct the misconvergence of the upper half and the lower half of the screen.

In the above embodiment, the correction coil device is provided with a pair of left and right E
Character-shaped magnetic bodies (11), (12) and 6 correction coils (31) ~
Although it is constituted by (36), the same effect as that of the above-mentioned embodiment can be obtained even if the correction coil which can be separated into three elements of the central portion, the upper side portion and the lower side portion is provided.

[Effects of the Invention] As described above, according to the present invention, it is possible to exert two functions of correction of coma aberration and correction of trilemma which is a component of misconvergence by using a single deflection yoke device. The design of the deflection yoke can be facilitated. Further, since the coma aberration and the misconvergence can be corrected in a non-linear manner, the upper and lower raster distortions are not changed, so that a high-quality convergence characteristic can be obtained over the entire screen.

[Brief description of drawings]

FIG. 1 is a front view showing the configuration of a correction coil device in a deflection yoke device according to an embodiment of the present invention, and FIG.
The wiring circuit diagram of the figure, FIG. 3 is a current waveform diagram for explaining the operation, FIGS. 4 and 5 are explanatory diagrams of the operation principle by the correction magnetic field, and FIGS. 6 and 7 are coma aberration and Yh error. Convergence correction characteristic diagram, FIG. 8 is a first quadrant diagram showing a misconvergence pattern, FIG. 9 is a misconvergence pattern diagram before correction, and FIGS. 10 and 11 are coma aberrations and Yh errors in FIG. FIG. 12 is a general characteristic view of convergence, FIG. 12 is an external perspective view of a conventional deflection yoke device, and FIG. 13 is a front view of a main part of a conventional convergence correction device. (2) …… CRT network, (5) …… Vertical deflection coil,
(11), (12) …… E-shaped magnetic material, (31), (32) ……
Central correction coil, (33), (34) ... upper side correction coil, (35), (36) ... lower side correction coil, (61) to
(63) …… Variable resistance, (D1) to (D4) …… Diode. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A deflection yoke disposed at the neck portion of a cathode ray tube, and a rear portion of the deflection yoke, each pole having poles on the horizontal axes of three electron guns arranged in-line in the cathode ray tube, and the neck portion. A pair of central correction coils disposed on both sides of the horizontal axis, an upper side correction coil having poles on the upper diagonal of the horizontal axis, and a lower side correction coil having poles on the lower diagonal of the horizontal axis. A coil, and a first diode and a second diode which are connected in series to the upper side correction coil and the lower side correction coil, respectively, and which are connected in an anti-parallel relationship with the first and second diodes forming the upper side series connection body and the lower side series connection body. Third and fourth diodes connected in series with the parallel connection body of the upper side series connection body and the lower side series connection body, an impedance element for applying a voltage to the first and second diodes, 3rd and 4th die And an impedance element providing a voltage to the over-de, a deflection yoke apparatus is characterized in that so as to provide a vertical deflection current to the and the parallel connection body said central portion correction coil.