JPH0743930Y2 - Deflection yoke - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke for a cathode ray tube used in, for example, a small video camera.

[0002]

2. Description of the Related Art The distance from the center of deflection of a cathode ray tube to the fluorescent screen is not constant, but is short at the center of the screen and becomes longer toward the periphery. Therefore, even if the deflection angle per unit time is constant, the scanning speed of the electron beam on the phosphor screen is not constant, and the scanning speed is slow at the center of the screen and becomes higher toward the periphery.

In order to correct this, conventionally, a method of connecting an S-shaped correction capacitor in series with the horizontal deflection coil and appropriately selecting the capacitance thereof to resonate with the inductance of the horizontal deflection coil has been adopted.

FIG. 2 is a sectional view of a deflection yoke and a cathode ray tube manufactured by a conventional technique. 1 is a cathode ray tube, 2 is a deflection coil, 3 is an electron beam focusing magnet, 4 is a centering adjustment magnet, and 5 is a fluorescent surface of the cathode ray tube.

[0005]

In the structure of the deflection yoke as described above, the following problems have occurred in recent years as the image quality of the cathode ray tube has improved. That is, as a problem related to the deflection yoke, this method can completely correct one or two lines of the screen, but cannot correct other lines.

Although a normal cathode ray tube does not cause much trouble, it causes a trouble in a case where a scanning speed is required to be constant over the entire screen such as a beam index type color cathode ray tube.

[0007]

The present invention has been made in view of the above circumstances, and in a magnetic field focusing type cathode ray tube, a horizontal linearity correcting device is attached to the fluorescent screen side of the electron beam focusing magnet. Accordingly, the present invention aims to provide a deflection yoke whose scanning speed is constant over the entire screen.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a deflection yoke and a cathode ray tube according to an embodiment of the present invention. 1 is a cathode ray tube, 2 is a deflection coil, 3 is an electron beam focusing magnet, 4 is a centering adjustment magnet, and 5 is a fluorescent screen of the cathode ray tube. 6
Is a horizontal linear device attached to the fluorescent screen 5 side of the electron beam focusing magnet 3.

[0010]

As described above, in the deflection yoke of the present invention, in the cathode ray tube of the magnetic field focusing type, the horizontal linearity correction device is attached to the fluorescent screen side of the electron beam focusing magnet, so that the beam index color It is possible to provide a deflection yoke that requires a constant scanning speed over the entire screen, such as a cathode ray tube.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a deflection yoke according to the present invention.

FIG. 2 is a cross-sectional view showing an example of a conventional deflection yoke.

[Explanation of symbols]

 1 Cathode Ray Tube 2 Deflection Coil 3 Electron Beam Focusing Magnet 4 Centering Adjustment Magnet 5 Fluorescent Screen 6 Horizontal Linearity Correction Device

Claims (1)

[Scope of utility model registration request] 1. A deflection yoke for a magnetic field focusing type cathode ray tube, wherein a horizontal linearity correction device is mounted on the fluorescent screen side of the electron beam focusing magnet.