JPS62287789A - Automatic degaussing device for picture tube - Google Patents

Abstract

PURPOSE:To degauss all pieces of CRT under the same conditions by providing a capacitor arranged in parallel to a coil, an electric power source part to supply an electric power source to the coil, and a main control device. CONSTITUTION:When a switch 3 is turned off after a magnet relay 5 is put and the switch 3 is turned on, the parallel resonance is generated by a capacitor 8 and the first degaussing coil and the electric current waveform of the first degaussing coil 1 is attenuated. Since the magnetic flux of the first degaussing coil 1 is gradually attenuated by the waveform, the degaussing of a CRT 10 can be executed. The second degaussing coil 2 also simultaneously executes the degaussing. By executing the ON timing of the first degaussing coil 1 and the second degaussing coil 2 continuously from a main control device, the degaussing of the CRT 10 can be automatically executed.

Description

DETAILED DESCRIPTION OF THE INVENTION 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to an automatic degaussing device for CRTs in a picture tube (hereinafter abbreviated as CRT) inspection line.

Conventional technology Generally speaking, demagnetization technology involves applying a magnetic field to a CRT and gradually weakening it.
It was 11 by moving away from T.

Problems to be Solved by the Invention However, with the method described above, there are problems in that the degree of demagnetization varies depending on the skill and experience of the worker, that it takes a lot of man-hours for the worker because it is done by the worker, and that the demagnetization effect is not stable. It had a point. Therefore, the present invention aims to make the degree of demagnetization uniform and to reduce the number of steps for the operator.

Means for Solving the Problems and In order to solve the above problems, the CRT automatic degaussing device of the present invention includes a coil, a capacitor provided in parallel with the coil, a power supply section for supplying power to the coil, and a main controller. It is equipped with a configuration called a device.

Function: With the above configuration, the present invention performs parallel resonance between the coil and the capacitor, thereby attenuating the alternating current power flowing through the coil. As a result, the magnetic flux generated in the coil gradually attenuates, allowing demagnetization to occur.

EXAMPLE An example of the present invention will be described below based on the drawings. In the figure, 1 is a first coil that demagnetizes the front surface of the coil, and 2 is a second coil that demagnetizes the top surface of the coil. 7 is an AC power source for the coil, 3 is a switch that prevents current from flowing to the first coil, 4
6 is a switch for flowing current to the second coil, 6 is a magnetic relay that suppresses the induced electromotive force in the first coil while the second coil is demagnetized, and 6 is a switch that suppresses the induced electromotive force in the second coil while the first coil is demagnetized. It's a bad magnetic relay.

And 8 and 9 are the respective first numbers. This is a capacitor that causes resonance with the second coil.

When you turn on the magnetic relay 5, turn on the switch 3, and then turn off the switch 3, a parallel resonance will occur between the capacitor 8 and the first coil, and the current in the first coil will attenuate as shown in Figure 3. With this waveform, the magnetic flux of the first coil is gradually attenuated, so that the CRT can be demagnetized. The second coil is similarly demagnetized.

Further, by controlling the ON timing of the first coil and the second coil successively from the main controller, it is possible to automatically demagnetize the CRT.

Effects of the Invention As described above, the present invention utilizes parallel resonance between a coil and a capacitor, and can demagnetize all CRTs under the same conditions. Furthermore, demagnetization can be performed automatically, reducing the number of man-hours.

[Brief explanation of the drawing]

FIG. 1 is a degaussing circuit diagram of an automatic picture tube degaussing device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the positional relationship between a CRT and a degaussing coil, and FIG. 3 is a current waveform diagram of the degaussing coil. 1...First degaussing coil, 2...Second demagnetizing coil, 3...Switch, 4...Switch, 5...Kawa-McNet relay , 6...
Magnetic relay, 7... AC power supply, 8...
... Capacitor, 9... Capacitor.

Claims (2)

[Claims] (1) A device for demagnetizing the magnetic force of a picture tube, which supplies power to a coil installed near the magnetic force of the picture tube, a capacitor installed in parallel so that this coil can resonate in parallel, and the above coil. An automatic picture tube degaussing device consisting of a power supply unit that controls the power supply unit, and a main control unit that controls the power supply unit. (2) Provide at least two pairs of coils and capacitors, one on the front of the picture tube and the other on the top of the picture tube, and a switch between each coil and capacitor, one of which is activated. 2. An automatic picture tube degaussing device according to claim 1, wherein the picture tube automatic degaussing device is constructed such that the other one does not operate when one of the picture tubes is in operation.