KR820001037B1 - Magnetizing method for use with a cathode ray tube - Google Patents

Abstract

The method of creating magnetized regions within a magnetic material to be located adjacent a neck portion of a CRT is disclosed. The method comprises developing an appropriate magnetizing field that will magnetize magnetic zones within the magnetic material for creating the magnetized regions for producing an electron beam moving magnetic filed. An alternating polarity component magnetizing field is applied to each of the magnetizing regions for eliminating from the electron beam moving magnetic field a component contributed by relatively easily demagnetizable magnetic zones within the magnetized regions. The magnetized regions are thereby stabilized.

Description

Method of forming magnetization zone for cathode ray tube

1 is a magnetization apparatus useful in the practice of the present invention attached to a magnetic material on the neck portion of a cathode ray tube.

FIG. 2 is a partially enlarged cross-sectional view of the cathode ray tube of FIG. 1, showing static concentrating and color purity of three sets of inline beams of the cathode ray tube of FIG.

3 is a magnetization apparatus useful in practicing the method of the present invention comprising a plurality of windings wound around the neck of the cathode ray tube of FIG.

4 and 5 are cross-sectional views of the magnetizer of FIG.

FIG. 6 is a partial perspective view of the magnetizer of FIG. 1 useful for establishing color purity by removing a portion of the cathode ray tube and the magnetic material.

FIG. 7 shows magnetic lines of force and magnetic forces formed by the magnetizer portion of FIG. 1 shown in FIG.

8 through 10 are schematic diagrams for supplying current to the magnetization apparatus of FIG. 1 to implement the method of the present invention.

The present invention relates to a method of forming a magnetization region for use in a cathode ray tube.

Inline, as described in US Patent Application No. 819,093 (Korean Patent Application No. 78-2293) and US Patent Application No. 819,094 (Korean Patent Application No. 78-2302), issued July 26, 1977. The type color cathode ray tube is provided with a magnetic material in contact with the neck portion thereof, and is subsequently provided with a magnetization device composed of conducting wires of various arrangements. 3, in which a magnetization current having a suitable direction and peak value flows to a selected one of the conductors, and a magnetization region is permanently formed in the magnetic material, and the electron beam is moved to a predetermined form according to the magnetic field generated by the region, whereby static focusing is performed. The color purity of the inline electron beam of the bath is established.

Over time, ambient conditions, such as fluctuations in temperature or exposure to irregular stray magnetic fields, may cause undesirable beam shifts of about 0.04 mm or more, resulting in some undesirably poor defocusing and color purity degradation. It has been confirmed that it is desirable to create a magnetization region in the magnetic material in order to eliminate this undesirable movement of the beam.

According to a preferred embodiment of the present invention, a magnetic material provided in contact with a neck portion of a cathode ray tube includes a magnetization region for generating a beam moving magnetic field to move at least one set of electron beams into a predetermined form in the cathode ray tube. The method for generating a magnetization region comprises the steps of: generating a suitable magnetic field for magnetizing a magnetic region in the magnetic material and a component contributed by a magnetic region that can be relatively easily demagnetized from the magnetic field for moving the electron beam within the magnetization region; And a magnetizing agent, which makes it possible to stabilize the magnetization region even in the case of significant fluctuation of the magnetic field for moving the electron beam.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

In FIG. 1, a magnetizable seed type or band member 20 made of a magnetic material is provided in contact with the neck portion 21 of the cathode ray tube 22. This member 20 is long enough to surround the neck 21 and to leave a small gap so that the ends do not overlap. The component of the magnetic material of this member 20 can also be normal barium ferrite mixed with the rubber | gum or plastic binder. This member 20 can be fixed to the neck 21 by an adhesive or by winding a tape of thin nonmagnetic material around it.

Cathode ray tube 22 has three sets of inline electron guns 24, 25 and 26 for generating blue, green and red electron beams, respectively. Among them, the green electron gun 125 is shown along the central axis 53 of the tube. Around the neck portion 21, a raster forming deflection device 27 including normal horizontal and vertical windings is provided.

All three sets of in-line electron beams intersect at the face of the shadow mask 61 and the fluorescent screen 67 deposited on the face plate 63 of the cathode ray tube 22, through a suitable hole 62, as shown in enlarged sectional view 99 of FIG. Static focusing, or central focusing, is obtained when projected onto a common three-color phosphor. In addition, if three sets of inline electron beams are projected only on the corresponding phosphor stripes 64, 65 or 66, respectively, high color purity is obtained. Although not shown in FIG. 2, the projection spot diameter of the beam is larger than the width of one set of phosphor stripes of each color.

In order to obtain a static connection of three sets of non-electrode portions, a permanent magnetization region having appropriate polarity and strength is formed in the band-shaped magnetic member 20. In order to form this area, as shown in FIG. 1, a magnetization device 28 is provided around the magnetic member 20. As shown in FIG. The magnetization device 28 has an annular housing 29 of nonmagnetic material, as shown in FIGS. 1, 4 and 5, wherein a plurality of first cavities 101 to 112 are located at the central axis 53 of the tube. A plurality of second cavities 201 to 208 are respectively provided in the vertical first plane and in the adjacent second plane perpendicular to the central axis 53 of the tube. In each cavity, a front wheel is provided, and a plurality of first and second windings 301 to 312 and 401 to 408 are formed, respectively. Each winding has a terminal, not shown, to receive a magnetizing current for forming a permanent magnetization region.

As shown in the cross-sectional view of FIG. 4, in the first plane, the plurality of first windings are divided into first and second groups, each of which is equidistant from the neck portion 21 at 60 ° intervals, respectively. Consisting of six windings 301 to 306 arranged, of which the winding 301 is on the vertical axis 60 of the neck 21, the second group equally arranged six windings alternately with the windings of the first group at an angular interval of 60 ° Consisting of 307 to 312, of which the winding 307 is inclined 30 ° to the right of the vertical axis 60.

Further, as shown in the cross-sectional view of FIG. 5, in the second plane, the plurality of second windings are divided into third and fourth groups, and the third groups are each at an angular interval of 45 ° around the neck portion 21, respectively. Four windings 401 to 404 disposed, of which winding 401 is inclined 45 ° to the right of the vertical axis 60, and the fourth group is four windings inclined + 15 ° and -15 ° to the left and right of the inline axis 51, respectively. It consists of 405-408.

As fully described in the above-mentioned U.S. Patent Application No. 819,093, in which the windings are coupled as described above, when a magnetizing current is supplied to the windings 301 to 306 of the first group, a permanent magnetization region is formed in the member 20. As a result, a six-pole or third harmonic inner magnetic field is generated to impart horizontal motion in the same direction as the outer two sets of inline beams. In the same way, when the magnetizing current is supplied to the windings 307 to 312 of the second group, a six-pole inner magnetic field rotated by 30 ° from the magnetic field formed by the windings of the first group is formed, thereby giving vertical movement in the same direction as the outer two sets of inline beams. do.

When the magnetizing current is supplied to the windings 401 to 404 of the third group, a permanent magnetization region is formed in the member 20. As a result, a quadrupole or a second harmonic internal magnetic field is formed, and horizontal movement in the opposite direction to the outer two sets of inline beams is achieved. Is given. The even harmonic inner magnetic field that supplies the magnetizing current to the fourth group of the windings 405 to 408 is formed to impart a vertical cloud in the opposite direction to the outer two sets of inline beams.

By using the magnetization apparatus 28 that gives horizontal and vertical motions in the same and opposite directions to the outer two sets of electron beams, the outer two sets of electron beams can be statically focused on the center beam.

To establish the color purity of the three sets of inline electron beams, the magnetizer 28 has conductors arranged in a third plane perpendicular to the tube axis 53. As shown in FIGS. 1 and 6, four sets of wires 30 to 33 shaped to extend tangentially to the circumferential surface of the neck portion 21 are embedded in the annular housing 29. The cross section of the lead is circular or spherical, and there are spacers 97 and 98 between the leads 30, 31, 32 and 33.

The ends of the leads 30, 33 and 31, 32 are connected by connecting leads 34 and 35, respectively, and the other ends of the leads 30 and 31 are connected by the connecting leads 36, and the other ends of the leads 32 and 33 are terminal leads 37, respectively. , 38 is connected. A magnetization current is supplied to the terminal leads 37 and 38 to form a permanent magnetization region for establishing color purity.

When the conducting wires are connected as described above, four sets of conducting wires form two elongated conducting wire loops 39 and 40 as shown in Fig. 7, and as described above, any of the conducting loops is the circumferential surface of the neck portion 21. Extend in the tangential direction.

When the magnetization of the peak magnetizing current I flows through the conductive wire loop as shown by the arrow direction in FIG. 6, the direction of the current flowing through the conductive wire loop is in the direction of the arrow in FIG. 7, and the connecting wires and the terminal wires 34 to 38 are wound around the winding parts 41 to 44. Functionally displayed by

As fully described in the above-mentioned US Patent Application No. 819,094, the magnetization current forms a magnetization region in the material of the magnetic member, whereby the magnetization region is applied from the electron guns 24 to 26 as shown in FIG. Along the perpendicular magnetic lines 45-47 alternating with the beam. These magnetic lines of force generate horizontal forces and movements 48 to 50 to establish the color purity of the three sets of inline beams.

In order to obtain the magnetizing current, the current generating circuit 70 of FIG. 8 generates pulses of the magnetizing current at the output terminals 501,502.

The circuit 70 includes a charging circuit composed of a charge / discharge switch 71, a variable voltage battery 72, a resistor 73 and a capacitor 74, and a discharge path for the magnetizing current includes a resistor 75 and a two-pole double switch 76 for switching the current direction.

The magnetizing current pulse is supplied to the output circuit shown in FIG. The output circuit 80 has a rotation select switch 85 connected to the terminal 501, a plurality of conductor groups 301 to 306, 307 to 312, 401 to 404, 405 to 408, and an elongated conductor loop 39 and 40 of the magnetizing device 28. Is connected to the terminal of the selector switch 85 and the terminal 502.

If an electron beam error such as focusing error or color purity defect is found during operation of cathode ray tube 22, select switch 85 activates selection of a suitable conductor group and adjusts battery 72 to adjust the magnetization current of peak value suitable for the selected conductor group. Supplies a suitable permanent magnetization region within the magnetic member 20 and imparts an appropriate amount of beam modification motion.

Using the above sequence, it was confirmed that a slight undesirable amount of error motion occurs with the time other than the beam correction motion, thereby producing a slightly undesirable degree of beam misalignment.

A large part of this error motion is thought to be due to the change of the magnetic flux density at the electron beam position due to the potato phenomenon of the magnetic band in the permanent magnetization region of the magnetic member 20.

The magnetization current flowing through the selected conductor group becomes a magnetomotive source for generating the magnetic field force H in the magnetic member 20 adjacent to the conductor group, and the field of the magnetization force matches the magnetic efficiency of the element band in the direction of the field. By polarizing the magnetic band of the member 20.

A magnetic induction of the magnetic flux density B whose magnitude depends on the magnetic permeability of the material by the magnetizing force is formed, and after removing the magnetizing current and the magnetizing force, the residual induction of the magnetic flux density Bd remains in the member 20 to form the permanent magnetization region. Some of the magnetic flux generated by this residual induction intersects with the electron beam through a path in the air, forms a magnetic field of magnetic flux density for moving the power beam, and moves the power beam to a predetermined shape selected.

The magnetic flux density value for the beam moving according to the magnitude of the residual induction is determined by the intersection of the B-H induction characteristic curve of the magnetic material of the magnetic member 20 and the magnetic material of the member 20. This intersection, that is, the operating point, determines the values of residual induction and electron beam moving magnetic flux density. Appropriate operating points are obtained by appropriately selecting the peak magnetization current to determine the induction curve value with knowledge of the magnetic hysteresis of the material.

Much of the observed error motion is due to changes in operating points due to changes in ambient and internal conditions, such as exposure to drift magnetic fields, periodic changes in magnetic resistance in the temperature and air paths, or irregular structural instability of the data itself. I think. This conditional change causes the induced curve to follow a small hysteresis curve. If the original non-magnetizing material magnetizes a single or few magnetizing current pulses, the small hysteresis curve along its induction curve is not the same because it is only asymptotically close to the steady state one. The operating point of the magnetized material exposed to such a change in condition is different from the initial operating point obtained immediately after the magnetizing operation. It is thought that the change of this operating point produces an observable error motion in the electron beam.

On the other hand, it is also considered possible to explain that a large part of the error motion is caused by potatoes in the unstabilized magnetization zone in the permanent magnetization region of member 20. The residual induction remaining after magnetization is generated by the polarization zone of the magnetization region, but a part of this residual induction is generated by the relatively easily polarized portion in the magnetization region, that is, the magnetic material portion which can be magnetized with a relatively small magnetization force. One component of the field of magnetic flux density for electron beam transport is negative in this relatively easily polarized band.

Zones that can be polarized relatively easily can also be demagnetized relatively easily. That is, under the change of the ambient conditions, this is detected by generating a mismatch of the magnetic efficiency, and the field of the residual induction and the magnetic flux density for moving the electron beam is changed to cause an error movement of the electron beam.

One feature of the present invention is a method of forming a magnetized region that is stable to potatoes due to changes in ambient and internal conditions. This magnetization region is formed such that the band where the polarization or demagnetization can be relatively easily contributed substantially does not contribute to the field of the flux under the electron beam moving.

The current generating circuit 770 of FIG. 10 can be used in the practice of the present invention. When the electron beam error is found on the display surface of the cathode ray tube 22, the nature and quantity of the beam correction motion are judged to select an appropriate conductor group by the rotary switch 85 of FIG. 9 and the control arm 581 of the variable battery 579 of FIG. The peak value of the magnetizing current is appropriately selected by the position. This adjustment amount is demonstrated below.

The initial signal is supplied to the input terminal 574 of the bias and magnetization control device 503, and the first switching signal is supplied from the terminal 588 of the control device 503 to the control terminal of the controlled switches 571 to 573 to connect terminals A and C of each switch. To combine. The bias capacitor 582 is then charged from the battery 578 via the resistor 577. The polarity of the cell is chosen such that the charge on capacitor 582 is positive with respect to the ground point, for example as shown. The magnetizing capacitor 584 is charged from the variable battery 579 through a resistor 580 in a reverse polarity with the capacitor 582.

AC power supply 507 such as AC 120v and 60Hz line voltage is coupled to the variable tap section primary winding 509a of the variable transformer 509. The number of turns of the primary winding coupled to the AC power source 507 is determined by the position of the movable contact 508.

The secondary secondary winding 509b having ten fixed tabs 511 to 520 is magnetically coupled to the primary winding 509a, and each of the fixed tabs has ten half-wave rectifying diodes 521 to 530 and 10 as shown in FIG. 10 resistors 531 to 540, respectively, to 10 stabilizing capacitors 541 to 550, respectively. Ten diodes 521 to 530 are reverse polarity to each other and pass through an alternating cycle of secondary AC voltages induced when terminals A and C are coupled.

The ten stabilizing capacitors are alternately charged with reverse polarity, and the capacitor 541 and bias capacitor 582 at the left end of FIG. 10 are charged with the same polarity, that is, positive polarity. Since the winding ratio of each tap is constant, the voltage of the stabilizing capacitor is also reduced at a constant rate, the charge of the capacitor 541 is maximum, and the charge of the capacitor 550 at the rightmost end is minimized. In the example described below, the charge of the next stage capacitor is 92% of the capacitor charge of the preceding stage, and therefore the charge of the capacitor 550 is 47.2% of the capacitor 541. The charge of the first capacitor 541 is determined by the position of the movable contact 508.

The output line 590 is connected to the output terminal 50 of the output circuit 80 of FIG. 9, and the output line 591 is connected to the ground point and the output terminal 502. A bias capacitor 582, a magnetizing capacitor 584, and stabilizing capacitors 541 to 550 are connected between the output lines 590 and 591 via the anode cathode paths of silicon controlled rectifiers (SCR) 583, 585 and 551 to 560, respectively.

When one of the SCRs is conducted by a suitable control pulse, the corresponding capacitor discharges the current pulses from the output terminals 501,502 to a specific conductor group. After the charging of the entire capacitors 582, 584 and 541 to 550, one switching signal is supplied to the switches 571 to 573, whereby terminals A and C of each switch are cut off and terminal A is connected to the terminal D being cut off. .

As a result, a bias trigger pulse is supplied from the control terminal 587 of the control device 503 to the gate of the SCR 583, and the SCR conducts to discharge the capacitor 582. Thus, a positive bias current pulse is applied to a specific group of conductors to form a magnetization region having the magnetic band polarized in the first direction in the member 20. The voltage of the battery 578 is selected so that a relatively large bias current is obtained so that the magnetic region which can be easily polarized and the region which is difficult to polarize are also polarized in the first direction. The magnitude of the residual induction after the interruption of this bias current becomes larger than necessary to impart a crystal beam motion, and furthermore, the first operating point is set at a location with poor polarity.

The magnetization trigger pulse is applied to the gate of the SCR 585 from the control terminal of the controller 503 to appropriately correct the crystal beam momentum, and conducts the SCR to discharge the capacitor 584. As a result, a current pulse in the opposite direction to the previous bias current pulse, that is, a negative magnetization current pulse, is supplied to the specific conductor group. Thus, the band that has been polarized up to now is exposed to the magnetization force of reverse polarity to that caused by the Dicer current, and when the intensity of the magnetization force is sufficient, the magnetized band is polarized in the opposite direction. The magnetic induction causes the magnetic induction to follow the potato portion of the induction characteristic curve, and when the magnetizing current is interrupted, the magnetic induction returns to the small hysteresis curve to set the second operating point.

By appropriately selecting the magnitude of the magnetizing current by the adjusting arm of the battery 281, a second operating point having a residual induction of a size sufficient to produce a desired amount of crystal beam motion is set.

Ten stabilizing current pulses are sequentially supplied from the capacitors 541 to 550 to the output terminals and 501,502 to stabilize the polarized magnetic portion of the magnetization region in the magnetic member 20. This is initiated by an input signal applied from the bias force control device 503 to the stabilization order control device 504, and control pulses are sequentially applied to the gates of the SCRs 551 to 560 from the control terminals 561 to 570 to conduct the SCR. . In this order, the first capacitor 541 discharges, the next stage capacitor discharges, and finally the last capacitor 550 discharges. The apparatuses 503 and 504 may be configured with timers of, for example, Cignetics Corp., type 555, or the like. The starting pulse applied to terminal 574 of the device 503 is actually generated by instantaneously grounding terminal 574 of the device 503.

The first stabilizing pulse obtained from capacitor 541 is positive polarity and is reverse polarity with the magnetizing current pulse applied from capacitor 584 preceding it. Subsequent to this, each recognition pulse gradually decreases at a constant rate as described above.

In order for the pulses to alternate inverted polarity and gradually decrease in magnitude, some of the bands that can be relatively easily polarized as the pulse lasts, i.e., can be easily demagnetized, and the relatively potato-polarized bands polarized by the previous pulse If the number of pulses that are polarized in reverse polarity and gradually decrease in magnitude, i.e., 10, then nearly half of the relatively prone bands are polarized in reverse polarity with the other 1/2. In this way, the influence of this relatively prone band is canceled from the residual induction, and thus eliminated from the field of magnetic flux density for electron beam movement.

Therefore, only a band having a relatively difficult magnetization substantially affects the field of the magnetic flux density for electron beam movement, whereby the magnetization region is stabilized against changes in ambient conditions and internal conditions.

A stable operating point is established because only a relatively difficult magnetization band contributes substantially to residual induction.

Since the band which tends to be demagnetized by this series of stabilization pulses is effectively prevented from contributing to the movement of the electron beam, if the crystal motion generated by the preceding magnetizing current pulse is not actually larger than necessary, that is, the peak value of the magnetizing current Must be adjusted to produce excess crystal motion.

Therefore, when this stabilization operation is performed to remove the influence of the band that tends to be demagnetized, the subtractive motion, that is, the sedimentation motion caused by the removal, works together with the previous excess crystal motion to generate the desired total crystal beam motion. .

The required amount of the needle movement depends on the amount of error moment observed when the magnetic member 20 is exposed to the ambient conditions. As the error movement becomes larger, the needle movement necessary for erasing the tendency bands generated in the member 20 also increases. This settling momentum is determined by the setting of the movable contact 508, the positions of the tabs 521 to 530, and the stabilizing capacitor and the actual number used in the circuit of FIG.

The magnetizing device 28 and the member 20 are provided on the neck portion 21 in the vicinity of the electron gun structures G ₁ to G ₄ electrode structures (not shown) and other soft magnetic materials relatively close to the magnetic material of the member 20. The resulting magnetic field extends far enough from member 20 to magnetize with this magnetically soft material. Since the magnetic soft material is extremely polarized and is magnetized even when the size of the stabilization pulse obtained from the capacitor 550 is minimum, this also affects the field of the magnetic flux density for electron beam movement.

The material is exposed to various factors and decays over time to change the field strength of the magnetic flux density for electron beam movement. Thus, there is a need to eliminate one cause of this undesirable error motion.

Another embodiment of the present invention is to eliminate this misleading phosphorus. After the stabilization operation is completed, a start signal is applied to the element oscillator 50 by the control device 504. The ringing attenuation AC sine wave element current 589 of FIG. 10 is supplied to the element lead 52 via the terminals 575,576. As shown in FIG. 3, the element conductor 52 is composed of a plurality of conductors wound around the neck 21 and the annular housing 29 of the magnetizing device 28. The element current value is represented by I = Imax Sin (wt) e ^-t / ^T Is determined. The maximum current is sufficient for the element and the potato of the soft magnetic material outside of member 20, but not large enough to affect the magnetization of the stabilized magnetization region inside the member.

The current generation circuit 770 performs the operation automatically and quickly from the step of supplying the starting current to the input terminal 574 to supplying the device current to the device lead 52, and the operator performs accurate electron beam motion so that only the final result is observed. You can also make it visible only. If the beam error still remains, the control arm 581 of the battery 579 is reset and all processes are executed again.

EXAMPLE

A 13-inch, 90 ° deflection slotted mask inline cathode ray tube with a green electron gun was used. The alternating voltage is 25KV, the electron gun spacing is about 6.6mm, the nominal neck diameter is about 29.1mm.

Magnetic member 20 is about 96.5 mm long, about 17.1 mm wide, about 1.5 mm thick, and has a maximum gap width of about 2.5 mm.

The material component of this member is BH value 1.1 × 10 ¹⁶ Gauss Ersted with barium ferrite mixed with a rubber binder, and is a general tire compound 39900 available from General Tire And Rubber Co. Same thing as my brother.

All constants of magnetizer 28 are as follows. Each wheel of the four conductor groups was wound 7 times with copper wire No. 20 of about 5mm in diameter and about 6.4mm in length. The long, long wire loop for purity correction was made with a solenoid winding with a square cross section of about 1.14mm square. A width of about 5.7 mm in the direction and a length of about 49.2 mm along the neck circumference were formed, and the angular distance to the inline side was within 5 °.

Capacitors 582,584,541 to 550 were all made to the same capacity of 640 μF.

Each of the impedance R of each capacitor charged by the direction and the _{sub-conductors} of each group impedance R for each capacitor charged in the positive direction was as follows:

Group 1 R ₊ = 0.124Ω R_ = 0.152Ω

Group 2 R ₊ = 0.124Ω R_ = 0.152Ω

Group 3 R ₊ = 0.116Ω R_ = 0.144Ω

Group 4 R ₊ = 0.116Ω R_ = 0.144Ω

Purity Correction Line

Loop R ₊ = 0.128Ω R_ = 0.156Ω

Peak device current Imax = 7A W = 1000Hz T = 1 sec

The voltage of the battery 578 and the voltage of the capacitor 582 at +255 V are the highest voltage of the battery 579 and the maximum voltage at the time of charging the capacitor 584 at the position of the -45OV movable contact 508 and all constants of the voltage source 507 and the transformer 509 at the capacitor 541. It was selected to be + 160V. The positions of the tabs 511 to 520 were selected so that any one voltage of the stabilizing capacitor was 92 ° of a constant ratio of the capacitor voltage at the immediately preceding end thereof.

A static hatching error was determined by measuring the distance of red and blue horizontal vertical lines to the horizontal and vertical lines of rust at the center of the display surface by combining a cross hatch generator with a television receiver to form a grid-shaped test pattern on the cathode ray tube display surface. . The results were as follows.

R _HL ≒ -0.38 mm, that is, the enemy horizon was about 0.38 mm above the rust horizon.

B _HL ≒ + 1.78 mm, that is, the blue horizontal line was about 1.78 mm below the green horizontal line.

R _VL ≒ -1.78 mm, that is, the vertical line of the enemy was about 1.78 mm left of the vertical line of rust.

That is, B _VL = + 0.89 mm, that is, the vertical line of blue was about 0.89 mm to the right of the vertical line of rust.

The correction momentum required for each pilot group was calculated as follows.

4th group- (R _HL -B _HL ) /2≒-1.08mm

3rd group- (R _VL -B _VL ) /2≒-1.34mm

2nd group- (R _HL + B _HL ) /2≒0.70mm

Group 1- (R _VL + B _VL ) /2≒+0.49mm

Denotations indicate that the horizontal or vertical lines of the blue beam move upward or to the right, respectively.

Next, the procedure for activating the fourth group of conducting wires to obtain a quartz motion of about -10.8 mm will be described in detail. The rotary switch 85 was properly rotated to set the fourth conductor group to be activated, and the adjusting arm 581 was adjusted so that the voltage Vm of the magnetizing capacitor 584 was -316V and a start signal was applied to the terminal 574.

In this way, the peak bias current I _B = + 2198A was generated, and the vertical momentum generated in the reverse direction by the fourth group was about -8.06 mm, and the distance between the red and blue horizontal lines became R _HL -B _HL ≒ -9.14 mm.

Next, a peak magnetization current pulse Im = 2194A was generated, and the reverse vertical motion thereof was about 6.86 mm, and the distance between the red and blue horizontal lines was about +4.57 mm.

Since the horizontal lines of red and blue do not overlap each other and are about +4.57 mm apart, it is clear that the necessary excessive correction motion is caused by the magnetizing current pulse, and the amount of excess correction is about -2.29 mm.

Next, when the stabilization operation is started with the initial stabilization current pulse as Is = + 1380A, the operating point of the magnetic member 20 changes at the end of this, and a needle movement of about +2.29 mm occurs, whereby the horizontal lines of the red and blue overlap each other and focus. do.

By repeating the above steps for each of the remaining three groups of conductor diagrams, three sets of static focusing of inline beams were achieved.

The values of Ib, Im, and Is for the remaining conductor groups are as follows.

Claims (1)

A method of forming a magnetization region in which a magnetic field for moving an electron beam for moving at least one set of electron beams in a predetermined form is formed in a magnetic material disposed in contact with a neck portion of a cathode ray tube. The magnetic region in the magnetic material of is subjected to a first step of generating a magnetic field suitable for magnetization to form the electron beam moving magnetic field, and subjected to a relatively easily demagnetized magnetic region in the magnetization region from the electron beam moving magnetic field. And a second step of removing the component, thereby stabilizing the magnetization region and preventing a substantial change in the intensity of the electron beam moving magnetic field.

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