JPH0117086Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a centering adjustment device for a cathode ray tube, and is particularly suitable for application to a small cathode ray tube.

For example, in order to obtain a monitor image in a television camera, it has been considered to use a small electromagnetic focus type cathode ray tube as shown in FIG. In FIG. 1, 1 is a panel, 2 is a funnel, and 3 is a neck tube, and a deflection coil 4 is disposed on the funnel side of the neck tube 3. network tube 3
A cylindrical support member 5 is fixed at approximately the center of the support member 5, and a pair of annular permanent magnets 6 and 7 magnetized on opposite sides around the support member 5 are polarized so that a repulsive force acts on each other. The permanent magnets 6 and 7 are sequentially attached in the axial direction of the neck tube 3 so as to hold the
Focusing is performed by adjusting the interval between the two, and centering is performed by eccentrically moving the lens in the radial direction. Note that 8 is a sealing metal part of the electron gun.

That is, a receiver 9 fixed to the deflection coil 4 is integrally formed at one end of the support member 5, and a male thread 10 is integrally formed at the other end.
0, the permanent magnets 6 and 7 repel each other between the adjustment screw 11 and the receiver 9, so that one permanent magnet 7 is pressed against the receiver 9 and the other permanent magnet 6 is pressed against the adjusting screw 11, and is maintained in that state by friction between the receiver 9 and the adjusting screw 11. Note that 12 is a member for fixing the support member 5 and the like to the neck tube.

In the configuration of FIG. 1, permanent magnets 6 and 7 form a lens for the electron beam passing through network tube 3, and adjusting screw 11 changes the distance between permanent magnets 6 and 7, thus changing the magnetic flux density. Focusing can be performed by doing this.
Furthermore, the inner diameters of the permanent magnets 6 and 7 are made sufficiently larger than the outer diameter of the support member 5, so that centering can be performed by eccentrically operating the permanent magnets 6 and 7 with respect to the support member 5. .

In practice, such focusing and centering adjustments are made when assembling the cathode ray tube, and after the adjustments are completed, the permanent magnets 6, 7 and the adjusting screw 11 are fixed to the support member 5 with an adhesive.

With the configuration shown in FIG. 1, it is possible to form an image on the panel 1 according to the video deflection signal given to the deflection coil 4 with a relatively simple configuration. A compact cathode ray tube that can be easily adjusted can be obtained.

By the way, in the configuration shown in FIG. 1, when centering, the support member 5 of the permanent magnets 6 and 7
This is done by eccentrically adjusting the radial position of. This is done by arranging the permanent magnets 6 and 7 in such a manner that they repel each other, and the permanent magnets 6 and 7 are pressed against the receiver 9 and the adjustment screw 11, respectively, by this repulsive force. This takes advantage of the fact that permanent magnets 6 and 7 can be held due to friction.

However, since the adjustment of the eccentricity of the permanent magnets 6 and 7 is entirely determined by the adjustment staff, it is extremely difficult to make minute adjustments. In particular, since it is a small cathode ray tube, the space around the network tube 3 is actually narrow, making it even more difficult to perform adjustment work by moving the human fingers in a complicated manner. Furthermore, there is a risk that the positions of the permanent magnets 6 and 7 may shift between the time the centering operation is completed and the permanent magnets 6 and 7 are fixed.

In consideration of the above points, the present invention makes it possible to adjust the slight deviation of the permanent magnet and maintain the adjusted state easily and easily by performing the centering adjustment via an eccentric adjustment section with a simple configuration. This is an attempt to propose a centering adjustment device that can reliably perform the centering adjustment.

An embodiment of the present invention will be described below with reference to the drawings. In FIGS. 2 and 3, the inner diameter (for example, 11.5 [mm]) of the annular permanent magnets used as the permanent magnets 6 and 7 in FIG. outer diameter (e.g.
9.10 [mm]).
An eccentric adjustment portion 15 is fixed to the annular permanent magnets 6, 7 to support them at a position eccentric to the central axis of the support member 5 (in other words, the central axis of the neck tube 3).

In this case, the eccentric adjustment part 15 is a substantially annular plate having a half-moon shape, the outer diameter of which is selected to be approximately equal to the inner diameter of the permanent magnets 6 and 7, and the diameter of the support member 5 is set at a position eccentric from the center. A circular support hole 16 is provided which is slightly larger than the outer diameter. This eccentricity adjustment part 15 is fitted and fixed into the center holes of the permanent magnets 6 and 7, and the support member 5 is inserted into the support hole 16 so that it can rotate with an appropriate frictional force against the support member 5. is being done.

In the configuration shown in FIGS. 2 and 3, the eccentric adjustment section 1
5 supports permanent magnets 6 and 7 at positions that are always eccentric with respect to the support member 5, so that the magnetic flux distribution at each part in the cross section of the neck tube 3 is biased in a predetermined manner determined by the amount of eccentricity.

However, since this bias in magnetic flux distribution is actually given by two permanent magnets 6 and 7 (Fig. 1), the bias in magnetic flux distribution given to the beam of the neck tube 3 is actually given by two permanent magnets 6 and 7. permanent magnet 6,
It is thought that it is determined by the composite vector quantity when the bias of 7 is expressed as a vector quantity.

For example, as shown in FIG.
If the beam of the neck tube 3 is rotated in completely opposite directions as shown in FIG. On the other hand, as shown in FIG. 4C or FIG. 4D, if the two eccentricity adjusting parts 15 are rotated arbitrarily as necessary, the overall deviation received by the beam of the neck tube 3 will be two. A centering effect is provided in the direction and size depending on the relative rotational position of the eccentricity adjustment section 15.

Therefore, the eccentricity adjusting section 1 having the configuration shown in FIGS. 2 and 3
According to No. 5, it is possible to give the beam of the neck tube 3 a bias in the magnetic flux distribution of any size over a range of 360 degrees.

FIGS. 5 and 6 show other embodiments of the eccentricity adjustment part, in which the eccentricity adjustment part 18 has a rectangular ring shape in cross section with the center part of one side cut out, and It has a circular arc shape along the circular arc shapes of the permanent magnets 6 and 7.

This eccentricity adjustment part 18 is made of, for example, a synthetic resin material, and is fitted into a part of the arc of the permanent magnets 6 and 7 by pushing out the notch part 19, and in this state, the permanent magnets 6 and
7 onto the support member 5. In this way, the inner plate portion 20 of the eccentric adjustment portion 18 is sandwiched between the support member 5 and the permanent magnets 6, 7, so that the permanent magnets 6, 7 are biased with respect to the neck tube 3.

FIGS. 7 and 8 show other embodiments, in which the eccentric adjustment part 23 is configured to be integrally fixed to the permanent magnets 6 and 7, and is arranged along the sides of the permanent magnets 6 and 7. Extending ring-shaped side plate portion 24
and arc-shaped ribs 25 and 26 that rise in a right angle direction from the outer periphery of the side plate portion 24 at positions facing each other so as to sandwich the peripheral surfaces of the permanent magnets 6 and 7, and a position facing one of the ribs 25. , and a spacer portion 27 rising from the inner circumferential edge of the side plate portion 24 in a perpendicular direction. This eccentric adjustment part 23 is mounted on the support member 5 by inserting permanent magnets 6 and 7 between the collar parts 25 and 26 so as to sandwich the peripheral surface thereof, and inserting the center hole 28 of the side plate part 24 into the support member 5. do.

Here, the inner diameter of the center hole 28 of the side plate part 24 is selected to be slightly larger than the outer diameter of the support member 5, so that when the eccentric adjustment part 23 is rotated, the permanent magnets 6 and 7 are placed at the center of the support member 5. shaft (therefore the neck tube 3
The spacer section 27 is rotated eccentrically by the thickness of the spacer section 27 with respect to the central axis of the spacer section 27.

Thus, in the same manner as described above with reference to FIG. 4, it is possible to provide the beam of the neck tube 3 with an arbitrary deviation in the magnetic flux distribution over a range of 360 degrees.

FIGS. 9 and 10 show other embodiments, in which the eccentric adjustment section 31 is constructed integrally with the permanent magnets 6, 7. That is, the permanent magnets 6 and 7 are formed with their center holes 32 eccentrically positioned, and their inner diameters are selected to be slightly larger than the outer diameter of the support member 5. The support member 5 is directly inserted into the center hole 32, and by rotating the permanent magnets 6 and 7, a bias in the magnetic flux distribution is generated in the neck tube 3, and this can be adjusted by rotation.

In this case, both sides of the permanent magnets 6 and 7 are uniformly magnetized, and the magnetic flux distribution is biased in the neck tube 3 so that the magnetic flux density is greater in the part of the center hole 32 that has a larger magnetized area. arise.

As described above, by forming the eccentricity adjustment part that causes a bias in the magnetic flux distribution in the neck tube 3 together with the permanent magnets 6 and 7, centering can be easily performed. However, if the resulting bias in the magnetic flux distribution is too strong or the permanent magnets 6 and 7 are polarized and centering cannot be adjusted, the permanent magnets 6 and 7 should be adjusted as shown in FIGS. 11 and 12. A pole piece 35 made of a magnetic material and having approximately the same outer diameter and inner diameter is attached so as to run along the sides of the permanent magnets 6 and 7.

In this way, the magnetic flux generated from the permanent magnets 6 and 7 passes through the pole piece 35 and its center hole 3.
Insert 6. Therefore, the magnetic flux is collected by the low magnetic resistance of the pole piece 35, and even if the permanent magnets 6 and 7 have biased magnetism, the pole piece 35 equalizes the magnetic flux, thus facilitating centering.

As described above, according to the present invention, fine centering can be easily and reliably achieved by rotatably providing two sets of eccentric adjustment parts on the outer periphery of the neck tube, which cause a bias in the magnetic flux distribution with respect to the neck tube. A centering adjustment device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a left side view showing a small cathode ray tube to which the present invention is applied, FIG. 2 is a front view showing an embodiment of the cathode ray tube centering adjustment device according to the present invention, and FIG.
The figure is a sectional view taken along the - line, FIG. 4 is a schematic diagram for explaining its operation, FIG. 5 is a front view showing another embodiment of the present invention, and FIG. 6 is the - line.
7 is a front view showing still another embodiment of the present invention, and FIG. 8 is a sectional view taken along the line, FIG.
9 is a front view showing still another embodiment of the present invention; FIG. 10 is a sectional view taken along the - line; FIG. 11 is a front view showing the pole piece; FIG. 12 is a sectional view taken along line XII-XII. DESCRIPTION OF SYMBOLS 1... Panel, 2... Funnel, 3... Network tube, 4... Deflection coil, 5... Support member, 6,
7...Permanent magnet, 8...Sealing metal, 9...Receiver, 10...Male thread, 11...Adjustment screw, 12...
...Removal prevention member, 15, 18, 23, 31... Eccentricity adjustment part, 19... Notch part.

Claims (1)

[Claims for Utility Model Registration] 1. Two annular permanent magnets magnetized on opposing sides are arranged on a neck tube so as to generate a repulsive force to each other in the tube axis direction, and between the two permanent magnets, In a cathode ray tube in which focusing is adjusted by adjusting the interval between the two permanent magnets, the magnetic flux distribution applied to the network tube is biased based on the magnetic flux generated from the two permanent magnets. Two eccentricity adjustment parts formed by integrating said permanent magnets are each rotatably mounted on said neck tube, and centering adjustment is performed by relatively rotating said eccentricity adjustment parts. Cathode ray tube centering adjustment device. 2. The eccentric adjustment unit is rotatably mounted on the neck tube and holds the permanent magnet having a center hole at an eccentric position with respect to the neck tube. Cathode ray tube centering adjustment device. 3. The eccentric adjustment part is a circular hole provided in the permanent magnet and through which the neck tube is inserted, and the circular hole is formed at an eccentric position of the permanent magnet. Cathode ray tube centering adjustment device.