JPS587965Y2 - Convergence device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a convergence device used in a so-called in-line color cathode ray tube having a plurality of guns arranged in-line. An object of the present invention is to provide a device that can correct deviations.

Recently, three guns that generate three electron beams for R, G, and B are arranged in-line (generally arranged in a horizontal plane).
Color cathode ray tubes are often used.

In such an in-line type color cathode ray tube, the horizontal deflection magnetic field from the horizontal coil is made into a strong pincushion-shaped magnetic field, and the vertical deflection magnetic field from the vertical coil is made into a strong barrel-shaped magnetic field, as shown in Figure 1. Both the convergence deviation in the horizontal direction at the center of the screen and the convergence deviation in the vertical direction at the center can be reduced to zero.

This should enable a design that eliminates convergence shifts at the diagonal corners of the screen obtained by combining them, but in reality, when the screen size and deflection angle are enlarged. However, there is a problem in that the convergence shift cy at the corner in the diagonal direction does not become zero, and a vertical shift cy occurs.

Generally, this deviation appears as a cross-shaped deviation in which the side beams R and B located on both sides form trapezoids in opposite directions, as shown in Figure 1, and the magnitude of the deflection magnetic field due to the deflection yoke increases. Depending on the screen size or the deflection angle, the deviation will be as shown in the figure or in the opposite direction.

Such a convergence shift cannot be corrected by a static convergence magnet provided at the neck of the color cathode ray tube.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a convergence device that can effectively correct convergence deviations at the corners of the screen in such in-line color cathode ray tubes.

Therefore, the present invention is characterized in that a correction magnet is provided in a portion corresponding to the diagonal direction of the color cathode ray tube between the deflection yoke and the funnel portion.

An embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 2 shows the principle of the correction operation in the convergence device of the present invention, and this figure shows the case where correction is performed when a convergence shift occurs in the direction as shown in FIG.

As can be seen from the figure, in this device, correction magnets 2a, 2b, 2C, and 2d are provided at portions corresponding to the diagonal direction of the color cathode ray tube 1, respectively.
, B electron beams, which are deflected by the deflection yoke and pass through these diagonal directions, are corrected for the electron beams located on the outer side of the screen. I am trying to correct the convergence shift.

For example, in the upper right direction, the direction of the R electron beam out of the three electron beams 3a passing through this area is moved slightly upward by the magnet 2a as shown by the arrow in the figure. The convergence shift is corrected by moving the line created by the R electron beam in the upper right direction slightly upward.

Also in the upper left direction, lower left direction, and lower right direction, three electron beams 3b are generated by magnets) 2b, 2C, and 2d, respectively.
, 3C, and 3d.

Move the B and R electron beams a little as shown by the arrows,
Correct the convergence deviation in each part.

Note that 3e indicates an electron beam in an undeflected state.

If the convergence shift on the screen is opposite to that shown in Fig. 1, the magnets 2a to 2d to be provided are
Just reverse the polarity.

It goes without saying that the magnitude of the magnetic force and the mounting position of the correcting magnets 2a to 2d may be adjusted in accordance with the state of deviation in convergence so that the deviation in convergence can be corrected correctly.

Furthermore, if there is a corner where there is no deviation in convergence, it is not necessary to provide a magnet for that part, and it is sufficient to provide only the necessary part.

Using the principle described above, it is possible to correct the convergence shift as shown in Figure 1, but as shown in Figure 2, different electron beams are affected by different electron beams depending on the part through which the three electron beams 3a to 3d pass. In order to perform such correction, magnets 2a to 2d must be provided at positions after the electron beam has been deflected to a certain extent and at positions where a magnetic field can be selectively applied to the electron beam.

The only position suitable for this purpose is between the deflection yoke and the funnel portion of the cathode ray tube, and this device is characterized in that the correction magnets 2a to 2d are provided here.

Specifically, for example, as shown in FIG. 3, small plate-shaped magnets 2a to 2d are fixed to the inner surface of the deflection yoke 4 using an adhesive or double-sided tape, or as shown in FIG. As shown in the figure, a magnet is attached to one end of the elongated plates 5a to 5d (preferably made of non-magnetic material).
As shown in FIGS. 5 and 6, the plates 5a to 5d are inserted between the deflection yoke 4 and the funnel portion of the cathode ray tube 1, and the other plates 5a to 5d are fixed. The ends may be attached to the wall of the funnel portion using adhesive or double-sided tapes 6a to 6d.

This latter case is more convenient because the positions of the magnets 2a to 2d can be adjusted freely before installation.

4 and 5, 4a is an insulating frame of the deflection coil, 4b is a horizontal deflection coil, 4C is a vertical deflection coil (including a ferrite core), 4d is a tightening band thereof, and the front end of this deflection yoke 4 is Since the portion is supported by a wedge-shaped seat 4e slightly lifted from the funnel portion, there is sufficient clearance for providing the magnets 2a to 2d.

7 is a normal static convergence magnet.

As detailed above, the convergence device of the present invention eliminates misconvergence, especially at the corners of the screen, that occurs when using an in-line cathode ray tube, between the deflection yoke and the funnel part of the cathode ray tube, and in the diagonal direction. It is characterized in that a magnet is provided at the position and a correction magnetic field is applied to the outer one of the three electron beams to correct its direction. In this case,
The effect is that no matter how much misconvergence increases in any direction depending on the deflection angle or screen size, it can be corrected appropriately by changing the polarity, strength, and size of the magnet. .

Conventional methods that correct convergence by concentrating the magnetic field at the deflection corner using a magnetic material do not correct convergence in the direction of the barrel shape when the deflection magnetic field is distorted from a barrel shape to a bottle cushion shape at the periphery. Even if the electron beam is deflected into a barrel shape, the deflection magnetic field may be too strong or too weak for only the outer electron beam. In such a case,
There was a problem that the correction could not be made only by concentration of the magnetic field by the magnetic body, but the present invention does not rely on the concentration of the magnetic field by the magnetic body, but by providing a correction magnet to Since a correction magnetic field is actively applied to the beam, whether the deflection magnetic field is barrel-shaped or bottle-cushion shaped, all corrections are made by changing the polarity of the magnet. It has the advantage of being able to

Furthermore, even if only the deflection magnetic field for the outer electron beam is too strong or too weak, it can be favorably corrected by applying a correction magnetic field from a magnet to the outer electron beam.

[Brief explanation of the drawing]

Fig. 1 is a front view of the screen to explain the convergence deviation, Fig. 2 is a pressure-resistant side view to explain the principle of the convergence device of the present invention, and Fig. 3 is a convergence device in an embodiment of the present invention. FIG. 4 is a perspective view of a magnet used in a convergence device according to another embodiment of the present invention, and FIGS. 5 and 6 are a side view and a partially sectional view of the same device. 1...Color cathode ray tube, 2a-2d...
・Magnet, 3a-3e...Electron beam, 4
...Deflection yoke, 5a-5d...Plate body, 6a-6d...Adhesive or screen tape.

Claims (3)

[Scope of utility model registration request] (1) A deflection yoke is attached from the neck to the funnel of a cathode ray tube having a plurality of guns arranged in-line, and a portion corresponding to the diagonal direction of the color cathode ray tube is located between the deflection yoke and the funnel. Then, a correction magnetic field is applied to the outer electron beams among the plurality of electron beams generated from the plurality of guns, deflected by the deflection yoke, and passing through the diagonal corners, and the direction of the electron beams is changed. A convergence device equipped with a magnet that corrects convergence deviations at the corners of a screen. (2) The convergence device according to claim 1, which is a utility model, in which a magnet is fixed to the inner surface of a deflection yoke. (3) The convergence device according to claim 1, which is a utility model registration, wherein a magnet is fixed to one end of an elongated plate, and the other end of the plate is adhered to the wall of a funnel portion of a color cathode ray tube.