Fig. 1 is the oblique view that an embodiment of cathode ray tube of the present invention is shown.
Fig. 2 be illustrate supply with Fig. 1 in the ideograph of the revers voltage supply unit used of the voltage of deflecting voltage opposite polarity.
Shown in Fig. 3 is circuit diagram with Fig. 2 equivalence.
Fig. 4 is explanation effect of the present invention and ideograph from the leakage electric field of arrangement for deflecting is shown.
Fig. 5 is explanation effect of the present invention and illustrates according to of the present invention and the deflecting voltage synchronous waveform ideograph by the electric field that opposite polarity compensating electrode produced.
Fig. 6 be explanation effect of the present invention and Fig. 4 is shown with the electric field shown in Fig. 5 and synthesizes after the ideograph of electric field.
Fig. 7 is the ideograph of the current potential at explanation effect of the present invention and the assigned position place that is illustrated in electric field shown in Fig. 4 to Fig. 6.
Fig. 8 is the oblique view that the variation of compensating electrode of the present invention is shown.
Fig. 9 is the oblique view that other variation of compensating electrode of the present invention is shown.
Figure 10 is the oblique view that other variation of compensating electrode of the present invention is shown.
Shown in Figure 11 is the angular distribution of compensation effect of the leakage electric field of the cathode ray tube device shown in Fig. 1, Fig. 8 and Fig. 9.
Figure 12 is cathode ray tube device shown in Figure 1 is assembled into occasion in the cabinet illustrates the state in the cabinet that cathode ray tube device is assembled into as representative oblique view.
Figure 13 is the oblique view that the variation of revers voltage supply unit of the present invention is shown.
Figure 14 is the oblique view that other variation of revers voltage supply unit of the present invention is shown.
Figure 15 is that the part that an embodiment of cathode ray tube image display apparatus of the present invention is shown is dissectd oblique view.
Figure 16 is the oblique view that other variation of revers voltage supply unit of the present invention is shown.
Figure 17 is the sectional view that existing cathode ray tube device structure is shown.
Wherein, 10 is cathode ray tube, and 13 is arrangement for deflecting, and 14 is the revers voltage supply unit, and 15,43,61,62,63,64,83 are compensating electrode, and 80 is cathode ray tube image display apparatus.
(embodiment 1)
Adopt Fig. 1 to Fig. 7 that one embodiment of the present of invention are described.
Fig. 1 is the oblique view of the cathode ray tube device in the present embodiment, by cathode ray tube 10; Be installed in funnel 11 outsides of cathode ray tube 10, have the horizontal deflection coil of the electron beam deflecting scanning that the electron gun (not shown) that makes neck 12 inside that are inserted in funnel 11 penetrates and the arrangement for deflecting 13 of frame deflector coil; Obtain with the deflecting coil that is added to arrangement for deflecting 13 on the revers voltage supply unit 14 used of the voltage of deflecting voltage waveform opposite polarity; Add that revers voltage supply unit 14 compensating electrodes 15 with voltage deflecting voltage waveform opposite polarity that produce constitute.Revers voltage supply unit 14 adds deflecting voltage at input side, and an end of revers voltage lead-out terminal is connected on the compensating electrode 15, and the other end is connected on the earthing potential.On the surface of cathode ray tube, external conductive film 17 is arranged usually and explosion-proofly be with 18 as the place that is directed to earthing potential.Be to be connected to by a end explosion-proofly on 18, to follow the earthing potential conducting in the present embodiment with revers voltage supply unit 14.
Cathode ray tube 10 is and existing routine identical construction, mainly by the panel 16 on essentially rectangular surface and the funnel 11 formed glass shells of following this panel 16 to be connected; Be formed at the fluorophor screen of panel 16 inner faces; Constitute with the send as an envoy to electron gun of electron beam of fluorophor screen excitation luminescence of relative neck 12 injections that are inserted into funnel 11 of this fluorophor screen.
Be installed in the arrangement for deflecting 13 of the outside of funnel 11, by generation make the horizontal deflection magnetic field of electron beam along continuous straight runs deflection horizontal deflection coil, with produce make electron beam vertically the frame deflector coil of the vertical deflection magnetic field of deflection constitute.Usually, generally be to make the saddle saddle type that horizontal deflection coil, pair of right and left saddle type deflecting coil constitute as frame deflector coil, make horizontal deflection coil, the saddle ring type that constitutes as frame deflector coil of a pair of annular coil up and down by a pair of saddle type deflecting coil up and down by a pair of saddle type deflecting coil up and down.And add the assigned voltage waveform that changes with specified period respectively and produce magnetic deflection field at horizontal deflection coil and frame deflector coil.The occasion of horizontal deflection coil is generally the pulse-like voltage waveform of hundreds of-1kV.
From cathode ray tube device is to leak AC field.But after checking investigation, the inventor understands just that the reason that takes place is an arrangement for deflecting.Owing to synchronously provide the deflecting voltage that the time changes with deflection frequency, current potential in deflecting coil ground from the high-pressure side to the low-pressure side produces spatial variations, this current potential because with respect to earthing potential just all want height on the ground and and ground between the electric field that changes.
When adding deflecting voltage like this on the arrangement for deflecting, just produce the AC field that roughly changes synchronously with the deflecting voltage waveform from arrangement for deflecting.And this AC field leak into cathode ray tube device around.The present invention produces compensation to suppress the opposite AC field that this AC field is used, and synthetic two electric fields compensate and suppress AC field.
Below describe in detail for the structure that is used for this purpose.Present embodiment leaks AC field for compensation, as shown in Figure 1, has near the revers voltage supply unit 14 up and down a pair of compensating electrode 15 (compensating electrode of downside not shown) with the side wall portion that is disposed at panel 16.Revers voltage supply unit 14, as shown in Figure 2, coiling coil 21a, 21b on the ring-shaped magnetic core 20 of closed magnetic circuit, in coil 21a, pass to deflection current, the two ends of coil 21a are as the input side terminal, as the end 22 of the coil 21b of revers voltage lead-out terminal be connected to the compensating electrode other end 23 then with the earthing potential conducting.And when deflection current flows through coil 21a, in magnetic core 20, produce magnetic flux, and on coil 21b, produce induced electromotive force.Coil 21b goes up the direction of the electromotive force of generation and is determined by the direction by the magnetic flux in the magnetic core 20, therefore can't be opposite polarity with the deflecting voltage waveform, promptly works as the cool timing compensating electrode of deflection electricity and adds negative potential.Therefore, by with an end of outlet side as reference potential and earthing potential conducting and the voltage waveform 24b that fish is added in the voltage waveform 24a opposite polarity on the coil 21a is added on the compensating electrode.This equivalence circuit diagram just as shown in Figure 3 if draw.In Fig. 3, shown in 30 is the main deflection coil, is horizontal deflection coil at present embodiment, by the electric field of compensating electrode generation radiation with the leakage electric field opposite polarity that roughly changes synchronously with horizontal deflection.In addition, in the tired circuit diagram such as grade shown in Fig. 3 Bodhisattva, the voltage that a pair of up and down compensating electrode adds respectively is identical so represent with a representative.
Below adopt Fig. 4 to Fig. 7 to describe for the compensating action of leakage electric field in the present embodiment.What illustrate to Fig. 4 pattern is sometime electric field in the AC field that is produced by the arrangement for deflecting of cathode ray tube device.So-called pattern is approximate simply, and with and ground (earthing potential) between formed Potential distribution representative the cause of the electric field of arrangement for deflecting is shown.In the example shown in Figure 4, equipotential lines 40a is from the expansion of the center radiation shape ground of arrangement for deflecting, along with making the current potential step-down away from the center, then is to radiation direction from the center for the direction of power line 42a.Fig. 5 be equally pattern electric field sometime in the middle of the AC field of a pair of compensating electrode 43 up and down is shown.During Fig. 5, equipotential lines 40b is that the center is expanded with compensating electrode 43, owing to be what on compensating electrode 43, to add with the voltage of deflecting voltage opposite polarity,, then point to the screen direction in the screen front so the direction of power line 42b is pointed to the method for compensating electrode up and down at cathode ray tube device.Therefore among Fig. 6 leakage AC field and as shown in Figure 5 compensating electric field synthetic as shown in Figure 4.See Fig. 6 as can be known, can suppress to expand to the leakage electric field that cathode ray tube particularly shields the front on every side by configuration compensating electrode 43.Shown in Fig. 7 is A-A ' at Fig. 4 to Fig. 6, B-B ', the current potential in C-C ' cross section.Electric field can be used as the gradient of current potential and calculates.From Fig. 7 also as can be known, the electric field that is taken place by cathode ray tube is suppressed.
Compensating electrode is essential at the outer surface of cathode ray tube with insulation with the part of earthing potential conducting in addition.This is because just can not produce the cause of compensating electric field if compensating electrode does not keep insulating with the part of following the earthing potential conducting.
Below in the variation of compensating electrode of the present invention Fig. 8 to Figure 10 illustrate.Example shown in Figure 8 is to dispose a pair of compensating electrode 61 about the panel sidewall of cathode ray tube 10.Example shown in Figure 9 is panel 16 a sidewall complete cycles configuration compensating electrode 62 of penetrating pipe 10 at negative electrode.This occasion also can adopt the structure of Wire-wound on the complete cycle of panel 16 sidewalls, thereby make simple in structure.At this moment, its structure and example shown in Figure 1 relatively, though about also dispose compensating electrode 62 continuously, preferably make the current potential of compensating electrode 62 identical on complete cycle.Example shown in Figure 10 is at four angles of the panel 16 of cathode ray tube 10 place's configuration compensating electrode 63.Also have, the shape of compensating electrode also is not limited to the foregoing description, and various shapes such as discoid, quadrangle shape evenly can adopt.
With the angular distribution of Figure 11 and Figure 12 explanation for the leakage electric field of above-mentioned all compensating electrodes.Figure 11 illustrates the metallic cabinet that cathode ray tube device of the present invention is assembled in the casing and measures the result of leaking AC field.Figure 12 is with shown in the representative of the occasion of cathode ray tube device shown in Figure 1 for state in the cabinet 68 that cathode ray tube device is assembled into.Measure under the state in being assembled into cabinet, be in order to estimate near under the state of actual behaviour in service, the occasion of Fig. 1, Fig. 8 and the cathode ray tube device shown in Fig. 9 of compensating electrode is set in the screen front as shown in figure 11, compare with the cathode ray tube device of leakage electric field not being taken measures, leakage electric field is reduced by half.The angular distribution of electric field shown in Figure 11 compensation because be according to the casing that is assembled with cathode ray tube device in the correlation of cabinet change, so wish to determine aptly the allocation position of compensating electrode.In addition, if near arrangement for deflecting, dispose compensating electrode, just can make the distribution of the distribution of compensating electric field near leakage electric field.But,, be necessary to take other insulation measures for the reason of voltage-resistent characteristic aspect if configuration is necessary to make the opposite potential that is added on the compensating electrode to increase to about the hundreds of-1kV of deflecting voltage degree during compensating electrode near arrangement for deflecting.In fact be installed in the cabinet owing to cathode ray tube device, and beyond the screen front, leakage electric field to a certain degree be suppressed, thereby prevent that the measure of leakage electric field from being to manage to make the electric field that leaks out previously at screen to be suppressed just passable by cabinet.And, because approaching more screen front is promptly far away more from arrangement for deflecting, should be added in voltage on the compensating electrode just can hang down to be deflecting voltage roughly half is below the size, thereby to dispose compensating electrode near panel be desirable.
Like this, by near the position the panel, disposing compensating electrode, the electric field that leaks for the rear of cathode ray tube device then utilizes the shield effectiveness of cabinet, can reduce to be added in the voltage on the compensating electrode, thereby voltage-resistent characteristic is relatively good, and makes the employing simple structure realize that compensation suppresses to become possibility.
The variation of revers voltage supply unit further is shown among Figure 13 and Figure 14.Figure 13 is the electromotive force that utilizes the magnetic flux in the main deflection magnetic field of arrangement for deflecting 70 to respond to.The ring surface of coil 72 is to point to tube axial direction so that near the lip portions 71 of the panel side of arrangement for deflecting 70 ring surface of leaked magnetic flux thorough coil 72.Figure 14 utilization be leakage field bucking coil 73.Owing to produced leakage field from cathode ray tube device, thereby, dispose and be wound on formed leakage compensation coil 73 on the magnetic core 75 with the coil 74 that produces with the reverse magnetic field of leakage field passing to the synchronous electric current of deflection current for suppressing this leakage field.Therefore be with magnetic core 75 same magnetic cores 75 that coil 74 is reeled on the coil 76 that is connected with compensating electrode of reeling utilize induced electromotive force.At this moment compensating electrode itself is not owing to there is electric current to flow through, thereby loses lessly, and the reduction of the compensating action of leakage field is less.Thereby, can make the leakage electric field leakage field be subjected to together suppressing effectively.
As mentioned above, its another advantage is, can suppress simply with the synchronous leakage electric field of deflection by the configuration compensating electrode, thereby there is no need in the screen front special electromagnetic wave shielding plate to be set, and the screen front does not consider that electromagnetic wave shielding just can implement shielding for example measure taked of anti-glare characteristic of the desired characteristic in front.
Also have, the present invention can suppress the structure of leakage electric field by adding the voltage opposite with deflecting voltage, the number of compensating electrode, position, size etc. are set can consider to use the size of cathode ray tube device of the present invention, leakage electric field distribution, inhibition level etc. and carries out suitable setting.Specifically, the relation of the position between the part that is necessary to consider compensating electrode and form earthed voltage.Be added in big or small identical that the size of the voltage on the compensating electrode may not be with deflecting voltage in addition, can suitably adjust the size of the voltage that adds according to the position of compensating electrode, length etc.The adjustment of the voltage that adds can be implemented simply by the number of turn of adjusting coil shown in Figure 2.But also can change be added in a pair of compensating electrode up and down shown in Figure 1 or pair of right and left compensating electrode shown in Figure 8 up and down or about voltage.
Also have, the foregoing description be as tackle the VLF that causes horizontal deflection (than low frequency: measure 2kHz-400kHz), to add on the compensating electrode be added in horizontal deflection coil on the opposite voltage waveform of voltage waveform be illustrated.But the invention is not restricted to the foregoing description, as tackling the ELF (extremely low frequency: measure 5Hz-2kHz) that cause vertical deflection, can add on the compensating electrode be added in frame deflector coil on voltage waveform opposite voltage waveform, measure that tackles VLF and the measure that tackles ELF are carried out simultaneously, independently compensating electrode is set respectively.
(embodiment 2)
Below adopt Figure 15 that other embodiment of the present invention is described.Figure 15 is that the part that cathode ray tube image display apparatus of the present invention is shown is dissectd oblique view, and cathode ray tube image display apparatus 80 forms the structure that cathode ray tube 82 is set in casing 81 inside.And, the panel sidewall of casing 81 inner cathode ray tube apparatus up and down near disposed the compensating electrode 83 that adds with the voltage of deflecting voltage waveform opposite polarity.
This compensating electrode 83 is to add with the voltage of deflecting voltage opposite polarity by having the revers voltage supply unit 84 that is shown in the structure among Fig. 2 identical with the foregoing description 1, and the revers voltage supply unit also can use identical with the foregoing description 1 and be shown in part among Figure 14 and Figure 14.Further, in the occasion of cathode ray tube image display apparatus, the bottom in casing 81 has kickback transformer and produces deflecting voltage by this usually, thereby as shown in figure 15 can be by coil 91 is wound on the flyback magnetic core 90 as the revers voltage supply unit.And then directly obtain on the basal disc in the casing with deflecting voltage synchronous waveform and opposite polarity voltage waveform also be possible.And compensating electrode also can be all distortion shown in Fig. 8 to Figure 10 of embodiment 1.
The effect of present embodiment is extremely shown in Figure 7 as Fig. 4 of above-mentioned embodiment 1 basically, be to make the electric field that the arrangement for deflecting of the cathode ray tube device of not implementing occasion of the present invention leaks out and add that the electric field that compensating electrode produced with the voltage of deflecting voltage opposite polarity synthesizes to suppress leakage electric field.But cathode ray tube device is arranged in the casing, thereby the state of the state of earthing potential and embodiment 1 is different, but basic principle is identical.
And cathode ray tube image display apparatus is that cathode ray tube device is assembled in the interior metallic cabinet of casing, and the part that forms except that screen is all used plated structure.Thereby cathode ray tube up and down and the electric field that leaks of rear by metal cabinet alleviating to a certain degree arranged.Certainly there is not the shield effectiveness of desired cabinet can suppress by compensating electrode itself yet, at this moment be necessary near arrangement for deflecting, to dispose compensating electrode as the center of leakage, and make the voltage that is added on the compensating electrode bring up to hundreds of volts-1kV size, thereby voltage-resistent characteristic is good inadequately.Therefore if cathode ray tube image display apparatus about, about suppress by cabinet, and the electric field that leaks with screen the place ahead is that the center takes some countermeasures, and the voltage that is added on the compensating electrode is reduced, thereby voltage-resistent characteristic is better.
Compensating electrode is arranged on the panel sidewall of the cathode ray tube device in the casing in the present embodiment, and the invention is not restricted to this.Promptly also compensating electrode can be configured in the inboard of casing front, can dispose integratedly with the anti-magnetized coil that is arranged in the common cathode ray tube image display apparatus again.More fortunately can produce on the appropriate location of the opposite electric field that is compensated leakage electric field and dispose compensating electrode.Occasion in the inboard that is disposed at the casing front can not dispose compensating electrode on the casing wall of contact side with cathode ray tube device, thereby realizes the insulation with the part of earthing potential conducting easily.
As mentioned above, its another advantage is to be suppressed owing to making simply with the synchronous leakage electric field of deflection by the configuration compensating electrode, thereby need not special electromagnetic wave shielding plate be set in the screen front, the screen front does not consider that electromagnetic wave shielding also can realize at for example measure taked of anti-glare characteristic of screen front desired characteristic.
In addition, the present invention is can be by having added the structure that suppresses electric field with the compensating electrode of deflecting voltage opposite voltage, the number of compensating electrode, position, size etc. are set can consider to use the setting that the distribution of the size of cathode ray tube image display apparatus of the present invention, leakage electric field, inhibition level etc. suit.Specifically, be necessary to consider the position relation of compensating electrode and the part that forms earthed voltage.And then being added in big or small identical that voltage swing on the compensating electrode may not be with bias voltage may, suitable adjustment is carried out to the voltage swing that is added in the position, length that can lean on compensating electrode etc.The adjustment of the voltage that is added can realize simply by the number of turn of adjusting coil shown in Figure 2.And can change a pair of compensating electrode up and down shown in Figure 1 or pair of right and left compensating electrode shown in Figure 8 up and down or about the voltage that added.
Also have, the foregoing description is as the measure that tackles the VLF (2kHz-400kHz) that causes horizontal deflection, for adding that on compensating electrode the voltage waveform opposite with the voltage waveform that is added in horizontal deflection coil is illustrated, but the invention is not restricted to the foregoing description, as the measure that tackles the ELF (5Hz-2kHz) that causes vertical deflection, add on the compensating electrode be added in frame deflector coil on the opposite voltage waveform of voltage waveform, measure that tackles VLF and the measure that tackles ELF are carried out simultaneously, independently compensating electrode is set respectively.
As mentioned above, cathode ray tube device of the present invention and cathode ray tube image display apparatus are added with and the deflecting voltage synchronous waveform and the compensating electrode of opposite polarity voltage waveform therewith by disposing at least one, and leakage electric field is easily suppressed.