JPH064524Y2 - Deflection yoke for small cathode ray tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a deflection yoke for a small cathode ray tube used in a viewfinder of a small video camera.

(Prior Art) As shown in FIG. 2, a conventional viewfinder has a centering magnet 16 and a focus magnet 17 (1) behind a horizontal deflection coil 12 and a vertical deflection coil 13.
7 ') was mounted on the outer circumference of the holder 15. However, with the widespread use, it is desired that a compact and lightweight video camera which is not only improved in performance but also convenient to carry is to appear, and efforts are being made to realize it. Therefore, the parts used in the video camera are also smaller,
Small cathode ray tube used for viewfinder (CR,
Abbreviated as T. ) Also needs to be small. If the overall length of the CRT is shortened to reduce the size, the horizontal and vertical deflection coils are inevitably shortened (because the position of the centering magnet moves forward), and the deflection power decreases accordingly. As a means for correcting the amount of decrease, there is a method of increasing the deflection current or the inductance of both deflection coils, but there are problems such as an increase in power consumption, an increase in weight, and an increase in external dimensions. In particular, increase in power consumption of video cameras that use batteries must be avoided as much as possible.

(Problems to be Solved by the Invention) The present invention aims to obtain a small-sized, power-saving type deflection yoke for a CRT that eliminates the above-mentioned problems.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a centering magnet or a centering magnet and a focus magnet mounted on the outer periphery of the rear end of a horizontal deflection coil having a long overall length. Characteristic deflection yoke for CRT.

(Operation) The present invention reduces the power consumption by increasing the total length of the horizontal deflection coil to increase the inductance.

(Embodiment) FIG. 1 is a partial vertical cross-sectional view of a deflection yoke for a CRT according to the present invention in which a centering magnet and a focus magnet are mounted on the outer periphery of the rear end portion of a horizontal deflection coil, which will be described below with reference to the drawings.

A trumpet-shaped horizontal deflection coil 2 and a vertical deflection coil 3 are mounted on the outer circumference of the neck portion of the CRT 1, and a shield plate 4 covers these outer circumferences. The total length of the horizontal deflection coil 2 is longer than that of the vertical deflection coil 3, and is extended rearward. A center ring magnet 6 and a focus magnet 7 are mounted on the outer circumference of the extended horizontal deflection coil 2 via a holder 5.

According to the experiment, when the total length of the CRT is shortened by a little less than 1 cm, the deflection power that decreases when the lengths of the horizontal and vertical deflection coils are simply shortened in accordance with it can be corrected as shown in FIG. It is necessary to increase the current consumption by about 20% compared to the conventional deflection yoke for CRT. However,
In the CRT deflection yoke according to the present invention shown in FIG. 1, the total power consumption does not change even if the vertical deflection current is increased.

Incidentally, it is obvious that the other focus magnet 7'can be mounted on the outer periphery of the rear end portion of the horizontal deflection coil by further extending the entire length of the horizontal deflection coil 2.
The embodiment of claim 1 is omitted as represented by FIG.

(Effect) As described above, the deflection yoke for CRT according to the present invention, which has the center ring magnet or the center ring magnet and the focus magnet mounted on the outer circumference of the rear end portion of the horizontal deflection coil which is longer than the vertical deflection coil, also has the outer dimensions. Since it remains almost unchanged and the current consumption does not increase, it greatly contributes to downsizing of the video camera.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view of a deflection yoke for a small cathode ray tube according to the present invention, and FIG. 2 is a partial vertical sectional view of a conventional deflection yoke for a small cathode ray tube. 1,11: Small cathode ray tube, 2,12: Horizontal deflection coil, 3,13: Vertical deflection coil, 4,14: Shield plate, 5,15: Holder, 6,
16: Center ring magnet, 7,17,7,17 ': Focus magnet, 8,18: Round nut, 9,19: Tightening ring.

Claims (2)

[Scope of utility model registration request] 1. A deflection yoke for a small cathode ray tube, wherein a centering magnet is mounted on the outer periphery of the rear end portion of the horizontal deflection coil in the deflection yoke attached to the neck portion of the small cathode ray tube. 2. A deflection yoke for a small cathode ray tube according to claim 1, wherein a centering magnet and a focus magnet are mounted on the outer periphery of the rear end portion of the horizontal deflection coil.