JP2550500B2 - Deflection yoke device for cathode ray tube - Google Patents

Description

TECHNICAL FIELD The present invention relates to a deflection yoke device for a cathode ray tube (hereinafter referred to as CRT) having an in-line array electron gun.

[Prior Art] In a deflection yoke device for a CRT having an in-line array electron gun, a vertical deflection current or a part of the vertical deflection current is shunted and supplied for various misconvergence correction purposes. And an auxiliary coil.

Conventionally, a resistor or a variable resistor has been used when the vertical deflection current is shunted and supplied to the auxiliary coil. For example,
FIG. 7 is a connection diagram showing a deflection yoke device described in Japanese Patent Laid-Open No. 58-212039, which is usually used to correct misconvergence called YH.

In FIG. 7, (1) is a vertical deflection circuit, (2) is a vertical deflection coil, (3) is a variable resistor connected in series to the vertical deflection coil (2), and (4) is a full wave. Rectifier diodes (5a) and (5b) are auxiliary coils.

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

When a vertical deflection current Iv as shown in FIG. 4 (c) flows through the vertical deflection coil (2), this vertical deflection current Iv is shunted according to the resistance value of the variable resistor (3), and the shunt current is a diode. (4) is full-wave rectified, and the forward voltage of the diode (4) causes the auxiliary coil current Ic having a non-conducting portion in the central portion of the vertical scanning as shown in FIG. 4 (e). It flows to (5a) and (5b). This auxiliary coil current Ic is adjusted by the variable resistor (3).

As shown in FIG. 3, the auxiliary coils (5a) and (5b) are magnetic bodies (7) arranged on both sides of the neck portion (6) of the CRT.
It is wound around a) and (7b), and when the above-mentioned auxiliary coil current Ic is supplied, it is set so that magnetic flux is generated in the direction shown in (B) in FIG. As a result, the misconvergence YH as shown in FIG. 8 is corrected.

[Problems to be Solved by the Invention] Since the conventional deflection yoke device for CRT is configured as described above, the vertical deflection current is shunted by the resistor or the variable resistor to supply the auxiliary coil current. As shown in FIG. 4 (e), there is a problem that waveform distortion (τ) is generated in the auxiliary coil current on the start side of vertical scanning. Especially when used in the correction device for misconvergence YH,
After the correction of YH, as shown in FIG. 9, a correction error (τ1) occurs at the upper end of the screen.

Further, the waveform distortion (τ) is caused by the auxiliary coils (5a), (5
If the inductance in b) is Lc and the internal resistance is Rc, it is due to the Lc / Rc ratio. To reduce such waveform distortion (τ), the Lc / Rc ratio must be reduced. However, there is a drawback that the design of the auxiliary coil is restricted.

The present invention has been made in order to solve the above problems, and is a deflection yoke for a CRT capable of supplying an auxiliary coil current with less waveform distortion, without adding any restriction on the design of the auxiliary coil. The purpose is to provide a device.

[Means for Solving the Problem] In a deflection yoke device for a CRT according to the present invention, an impedance element is connected in series with a vertical deflection coil, and an auxiliary coil is connected in parallel with this impedance element. Further, the impedance element is configured by a series body of an inductance variable coil and a variable resistance, and the (inductance / resistance) ratio of the impedance element can be adjusted according to the (inductance / resistance) ratio of the auxiliary coil. It is characterized by

[Operation] According to the present invention, the vertical deflection current is shunted by the impedance element to supply the auxiliary coil current to the auxiliary coil. Therefore, the ratio of the inductance to the resistance of the impedance element is set according to the same ratio of the auxiliary coil. By adjusting, the waveform distortion of the auxiliary coil current on the vertical scanning start side can be removed.

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

FIG. 1 is a connection diagram of a deflection yoke device for a CRT according to an embodiment of the present invention.

In FIG. 1, (9) is an impedance element for shunting the vertical deflection current Iv to obtain an auxiliary coil current Is, which is composed of an inductance variable coil (10) and a variable resistor (3). Since other configurations are the same as those of the conventional example shown in FIG. 7, corresponding parts are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 2 is a configuration diagram showing an example of the variable inductance coil (10). In the figure, (11) is a coil, (12) is a coil bobbin, and (13) is a ferrite screw core, which moves in the direction of the arrow in the figure. By doing so, the inductance can be adjusted.

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

When the vertical deflection current Iv shown in FIG. 4 (a) flows through the vertical deflection coil (2) connected to the vertical deflection circuit (1), both ends of the impedance element (9), that is, point A
Between point B and point B, the voltage Vs has the waveform as shown in Fig. 4 (b).
Occurs.

Here, when the inductance of the impedance element (9) is Ls and the internal resistance is Rs, and the Ls / Rs ratio is increased, the peak shape of the voltage waveform Vs becomes larger, and the auxiliary coil current Is is shown in FIG. It becomes like (d). Further, as the Ls / Rs ratio is reduced, the voltage waveform Vs approaches a sawtooth wave, and the auxiliary coil current Is approaches a conventional distorted waveform as shown in FIG. 4 (e).

Therefore, by appropriately selecting the Ls / Rs ratio of the impedance element (9) according to the Lc / Rc ratio of the auxiliary coils (5a) and (5b), as shown in FIG. 4 (c), The waveform distortion on the vertical scanning start side of the auxiliary coil current Is is eliminated.

The auxiliary coils (5a) and (5b) are set in the same manner as in the conventional example of FIG. 3, and are configured to correct the misconvergence YH.

As described above, the misconvergence YH in FIG. 8 can be satisfactorily corrected over the entire screen without causing the correction error (τ1) as shown in FIG.

Further, in the above embodiment, the case where the auxiliary coil current is full-wave rectified has been described. However, for example, the circuit configuration may be as shown in FIGS. 5 and 6, and FIGS.
The auxiliary coils (14), (15), and (16) in the figure are not limited to YH correction coils, but in the case of supplying a part of the vertical deflection current to the auxiliary coil, Has the same effect as.

In addition, (D1) to (D4) in FIGS. 5 and 6 are diodes.

As described above, according to the present invention, when a part of the vertical deflection current is supplied to the auxiliary coil, a predetermined impedance element is provided to eliminate the waveform distortion of the auxiliary coil current. be able to. As a result, there is an effect that there is no restriction on the design of the auxiliary coil and that a good correction characteristic can be obtained by applying the auxiliary coil to the misconvergence correction device.

[Brief description of drawings]

FIG. 1 is a connection diagram of a deflection yoke device for a CRT according to an embodiment of the present invention, FIG. 2 is a configuration diagram of an inductance variable coil, and FIG. 3 is a configuration diagram of a correction device used for YH correction,
FIG. 4 is a current / voltage waveform diagram for explaining the operation, and FIG.
FIG. 6 and FIG. 6 respectively show another embodiment of the present invention.
CRT deflection yoke device connection diagram, FIG. 7 is a conventional CRT deflection yoke device connection diagram, FIG. 8 is a YH misconvergence pattern diagram, and FIG. 9 is a correction error during YH correction by a conventional correction device. It is explanatory drawing which shows an example. (1) ... vertical deflection circuit, (2) ... vertical deflection coil,
(3) …… Variable resistance, (5a), (5b) …… Auxiliary coil,
(9) ... Impedance element, (10) ... Variable inductance coil. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A deflection yoke device for a cathode ray tube comprising an in-line arranged electron gun and an auxiliary coil to which a part of a vertical deflection current is supplied, and an impedance element is connected in series to the vertical deflection coil. In addition, the auxiliary coil is connected in parallel to the impedance element, and the impedance element is composed of a series body of an inductance variable coil and a variable resistor, and the auxiliary coil has an (inductance / resistance) ratio. A deflection yoke device for a cathode ray tube, wherein the (inductance / resistance) ratio of the impedance element can be adjusted according to the above.