JPS5850609Y2 - deflection yoke - Google Patents

Description

[Detailed description of the invention] This invention relates to a deflection yoke for image pickup tubes such as vidicon, and aims to prevent the glass tube around the collimating lens electrode from being charged and the influence of noise generated by the deflection coil on the target electrode. be.

A conventional example will be explained with reference to FIG.

1 is an image pickup tube such as a vidicon, the outer periphery of which is covered with a glass tube.

Reference numeral 2 denotes an electrode for the collimating lens, to which a high voltage of several thousand volts is applied.

3 is a target electrode for extracting a video signal.

4 is a deflection coil for generating a deflection magnetic field.

5 is an alignment coil provided to correct the direction of the electron beam.

6 is a magnetic shield material that shields external magnetic fields such as geomagnetism.
Wound with permalloy, etc.

7 is a resin bobbin provided for assembling these coils and holding the image pickup tube.

9, the noise generated from the deflection coil 4 is transmitted to the target electrode 3.
It is an electrostatic shielding material provided to avoid affecting the
Generally, a conductive paint is applied to the bobbin 7, or a metal plate cut into a circular shape is used.

Reference numeral 8 denotes an electrostatic shield plate similar to the electrostatic shield material 9, which is made of a flexible printed circuit board etched into a comb shape or coated with conductive paint.

Furthermore, for electrostatic shielding, these conductive paint coatings and flexible printed circuit boards must be connected for grounding.

These conventional configurations require the use of expensive conductive paint, require grounding connections, and complicate assembly work.

On the other hand, due to the high voltage of the collimating lens electrode 2, the image pickup tube 1
The surface of the glass tube of the image pickup tube 1 is charged, and this charge is discharged to the target electrode 3, causing noise in the video signal. Therefore, an antistatic material is applied to the surface of the glass tube of the image pickup tube 1.

The application of this antistatic material to the glass tube also has problems such as the need for application time and the reduction in effectiveness due to uneven application.

The present invention solves these problems and provides a deflection yoke equipped with a shield structure and an antistatic structure that is inexpensive and easy to assemble.

FIG. 2 shows an embodiment of the present invention.

Numbers 1 to 8 are the same as in FIG.

A bobbin 7 made of resin is arranged around the outer periphery of the image pickup tube 1 such as a vidicon, and is equipped with a deflection coil 4 that generates a magnetic field for deflecting the beam. In the deflection yoke, a collimating lens is provided between the target electrode 3 for extracting video signals on the outer periphery of the glass tube of the image pickup tube 1 and the deflection coil 4. A conductive elastic body 10 having elasticity and a conductor is arranged in a ring shape in a portion close to the electrode 2 for use, and one end of this conductive elastic body 10 is attached to a tightening band 11.
Press it onto the glass tube of the image pickup tube 1.

At the same time, the other end of the conductive elastic body 10, which is the outer periphery, is fixed with an external magnetic shielding material 6 wound around the outer periphery, so that the conductive elastic body 10 and the magnetic shielding material 6 are crimped together. electrically connected.

As a result, by grounding this magnetic shielding material 6, the high voltage of the collimating electrode 2 of the image pickup tube 1 is induced in the glass tube around the collimating electrode 2.

The charged charges are grounded via the conductive elastic body 10 and further via the magnetic shielding material 6.

Therefore, it is possible to prevent the electrical charges on the glass tube of the image pickup tube 1 from being discharged to the target electrode 3 for extracting a video signal, thereby preventing noise from being generated.

Further, since the conductive elastic body 10 is filled from the glass tube part of the image pickup tube 1 to the inside of the magnetic shielding material 6 and is located between the deflection coil 4 and the target electrode 3 for extracting the video signal, Nozzles generated from the deflection coil 4 and affecting the target electrode 3 for extracting video signals can be prevented.

Further, by using the band 11, the image pickup tube 1 can be firmly grounded, and the image pickup tube 1 can be fixed to the deflection yoke 4 and the glass tube can be protected.

Further, the conductive elastic body 10 may be concentrically shaped and a portion thereof may be cut to facilitate assembly.

As the conductive elastic body 10, in addition to conductive rubber, a conductive resin having elasticity may be used to obtain the same shielding effect and antistatic effect, and materials having various resistivities can be used.

Furthermore, the electrostatic shield plate 8 may be grounded by the conductive elastic body 10 using a flexible printed circuit board or the like, and in this case, further grounding of the electrostatic shield plate 8 can be omitted.

This embodiment is shown in FIG. An electrostatic shield plate 8 is sandwiched and connected between the bobbin 7 and the conductive elastic body 10 by a band 11.

As described above, the deflection yoke according to the present invention has a conductive elastic body crimped onto it, so that the electric charge that is accumulated on the glass tube of the image pickup tube due to the high voltage of the commate electrode of the image pickup tube is discharged through the conductive elastic body. Therefore, the charged charges will not be discharged to the target electrode for taking out the video signal, and noise generated thereby can be prevented.

Furthermore, since the conductive elastic body is installed between the deflection coil and the target electrode, noise generated by the deflection coil and induced into the target electrode can be blocked.

Furthermore, since electrical connection can be made simply by adhering the conductive elastic body, there is an advantage that there is no need to further connect a conducting wire for grounding.

[Brief explanation of the drawing]

Figure 1 is a partially sectional front view showing a conventional deflection yoke;
The figure is a partially sectional front view showing one embodiment of the deflection yoke according to the present invention, and FIG. 3 is a sectional view of main parts showing another embodiment of the present invention. 1... Image pickup tube, 2... Collimating lens electrode, 3... Target electrode, 4...
... Deflection coil, 5... Alignment coil,
6... Magnetic shielding material, 7... Bobbin, 8... Electrostatic shielding material, 10... Conductive elastic body, 11... ·band.

Claims (4)

[Scope of utility model registration request] (1) In the deflection yoke used for image pickup tubes such as vidicon,
A bobbin arranged around the outer periphery of the image pickup tube and provided with a deflection coil, and a magnetic shielding material wound around the outer periphery of the bobbin to be electrically insulated from the deflection coil and grounded. An elastic conductor is crimped to a portion of the outer periphery of the glass tube near the collimating lens electrode between the target electrode and the deflection coil, and the other end of the conductor is crimped to the magnetic shielding material. deflection yoke. (2) The deflection yoke according to claim 1, which is obtained by pressing a conductive elastic body onto a glass tube of an image pickup tube with a band. (3) The deflection yoke according to claim 1, which is a registered utility model and is formed by crimping and connecting a conductive elastic body to an electrostatic shield plate disposed between a deflection coil and an image pickup tube. (4) The deflection yoke according to claim 1, which uses conductive rubber as the conductive elastic body.