JPH0142463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color cathode ray tube.

FIG. 1 shows a conventional color cathode ray tube. As shown in the figure, a color cathode ray tube 1 includes a panel 2 having a fluorescent film (not shown) on the inner surface and serving as an image projection part, a funnel 3 connected to the panel 2 and having an approximately conical shape, and a funnel 3 having a substantially conical shape. A network part 4 consisting of connected glass cylinders, an electron gun 5 sealed in this network part 4 and generating an electron beam, and this electron gun 5
It consists of a lead-in wire 6, a base 7, etc., which is a terminal section for supplying voltage for operating the device. In order to operate such a color cathode ray tube, it is necessary to attach a deflection yoke 8 and a magnetic band 9 called a neck magnet to the neck portion 4.

The deflection yoke 8 is a magnetic device that deflects the electron beam from the electron gun 5 and directs it to a predetermined position on the fluorescent film provided on the inner surface of the panel 2, and is generally located at the connection point between the funnel 3 and the neck portion 4. Can be attached nearby.

The magnetic band 9 is used to magnetically correct the deviation of the overall and mutual irradiation direction of the plurality of electron beams emitted from the electron gun 5 from the required direction due to assembly errors during manufacturing or unnecessary internal and external magnetic fields. used for. Such a magnetic band is usually made of a sheet magnet made of magnetic powder such as barium ferrite and a binder such as nitrile rubber, and as shown by the shaded area in the unfolded state in Figure 2, it has a width of several mm. A magnetized region A having a width is formed.

The magnetized region A is formed by magnetizing using a magnetic head so as to impart magnetic anisotropy in a direction perpendicular to the sheet surface, and includes a dipole magnet component, a quadrupole magnet component, and a hexapole magnet component. This is a special magnetization pattern that combines the amount of magnetization required for correction. The amount of magnetization required for correction in this case can be calculated from the degree of deviation of the electron beam detected in front of the panel 2. Then, the magnetization pattern divides the magnetized region A that revolves around the neck portion 4 into several hundred minute regions, and depending on the above conversion value, each of these regions is set to either 0 magnetic field or saturated magnetic field. It is formed by setting the state.

However, as a result of detecting the amount of magnetization described above, if it does not have the specified accuracy, it is necessary to demagnetize the entire magnetized area and re-magnetize it based on the corrected value. It is common to repeat the detection, demagnetization, and magnetization operations about 10 times in order to achieve sufficient precision for correcting the beam's trajectory.
Therefore, the operation of magnetizing the magnetic band 20 is extremely inefficient and is a major hindrance in the manufacturing process of color cathode ray tubes.

The present invention has been made in order to improve the above-mentioned conventional drawbacks, and an object of the present invention is to provide a color cathode ray tube in which highly accurate magnetization of a magnetic band can be performed with good workability.

The present invention will be explained below with reference to the drawings.

FIG. 3 shows an embodiment of the color cathode ray tube of the present invention. In the figure, except for the magnetic band 9 arranged in a ring shape on the neck portion 4 of the color cathode ray tube 1,
This is the same as the conventional one shown in FIG. The magnetic band 9 has two band-shaped magnetized regions B ₁ and B ₂ , as shown by diagonal lines in the developed state in FIG.

In the above magnetic band, the amount of magnetization used to correct the deviation of the electron beam, that is, the amount of magnetization used for color purity adjustment, is
The magnetization pattern required for correction by combining the polar magnet component and the 4-pole magnet component and 6-pole magnet component used for static convergence adjustment is magnetized using two magnetizing heads (not shown). Form as regions B ₁ and B ₂ . In this case, if the widths of both regions are made different, for example, the width of magnetized region B ₁ is 3 mm and the width of B ₂ is 1.5 mm, the initial When there is an error with respect to the required amount of correction, that is, there is a correction remainder, it is sufficient to leave the magnetized region B ₁ as it is and re-magnetize only the magnetized region B ₂ for this correction remainder.

That is, in the magnetic band in the color cathode ray tube of the present invention, the wider magnetized region can absorb most of the amount of magnetization required for correction, and the narrower magnetized region can share the remainder. For this reason, even if a certain amount of error occurs during the first magnetization, there is no need to re-magnetize the entire thing, and the adjustment is made in a narrow magnetization area for the slight correction amount corresponding to the error. By doing so, it is possible to reach the desired correction accuracy in a short time.

In addition, in the above embodiment, a case was shown in which the magnetic band attached to the neck part has two magnetized regions, but in this invention, a magnetic band having three or more strip-shaped magnetized regions is attached to the neck part. Also includes color cathode ray tubes. In the case of a large number of magnetized regions like this, each magnetized region is configured to have a different width,
By performing the initial correction in the widest magnetized area, and as the amount of correction remaining decreases, corrections are sequentially performed in narrower magnetized areas, more accurate correction is possible.

[Brief explanation of drawings]

Fig. 1 is a schematic side view showing a conventional color cathode ray tube, Fig. 2 is a perspective view showing a developed state of the magnetic band used in the conventional color cathode ray tube, and Fig. 3 is a schematic side view showing a color cathode ray tube of the present invention. Schematic side view shown, No. 4
The figure is a perspective view showing a developed state of the magnetic band used in the color cathode ray tube of the present invention. 1...Color cathode ray tube, 4...Network section, 9...
...Magnetic band, B ₁ , B ₂ ... Magnetized region. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. An in-line type in which a ring-shaped magnetic band is attached to the neck part, in which magnets are formed to form a two-pole magnetic field for adjusting color purity and a four-pole magnetic field and a six-pole magnetic field for adjusting static convergence. A color cathode ray tube, characterized in that the magnetized region of the magnetic band is divided into a plurality of annular regions, and each of the annular magnetized regions has a different width.