EP0523741A1 - Dispositif de tube à rayons cathodique - Google Patents

Dispositif de tube à rayons cathodique Download PDF

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Publication number
EP0523741A1
EP0523741A1 EP92112290A EP92112290A EP0523741A1 EP 0523741 A1 EP0523741 A1 EP 0523741A1 EP 92112290 A EP92112290 A EP 92112290A EP 92112290 A EP92112290 A EP 92112290A EP 0523741 A1 EP0523741 A1 EP 0523741A1
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EP
European Patent Office
Prior art keywords
ray tube
cathode ray
deflecting
compensating
tube apparatus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP92112290A
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German (de)
English (en)
Inventor
Kouichi c/o Intellectual Property Div. Soneda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Publication of EP0523741A1 publication Critical patent/EP0523741A1/fr
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/003—Arrangements for eliminating unwanted electromagnetic effects, e.g. demagnetisation arrangements, shielding coils
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/70—Arrangements for deflecting ray or beam
    • H01J29/72—Arrangements for deflecting ray or beam along one straight line or along two perpendicular straight lines
    • H01J29/76—Deflecting by magnetic fields only
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/0007—Elimination of unwanted or stray electromagnetic effects
    • H01J2229/0015—Preventing or cancelling fields leaving the enclosure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/0007—Elimination of unwanted or stray electromagnetic effects
    • H01J2229/0046—Preventing or cancelling fields within the enclosure
    • H01J2229/0053—Demagnetisation

Definitions

  • the present invention relates to a cathode ray tube apparatus and a cathode ray tube image display apparatus, and more particularly, to a measure to counter leakage electric fields from the cathode ray tube apparatus and the cathode ray tube image display apparatus.
  • the cathode ray tube apparatus for deflecting electron beams for scanning, emitted from an electron gun, by means of a deflecting device, is set in a cabinet.
  • the cathode ray tube apparatus comprises an envelope formed of a panel 1 and a funnel 2, a phosphor screen 3 on the inner surface of the panel 1, the electron gun in a neck 4 of the funnel 2, and a deflecting device 6 mounted outside the funnel 2.
  • the electron gun emits electron beam for exciting the phosphor screen 3.
  • the deflecting device 6 generates a deflecting magnetic field which deflects the electron beam for scanning. It is necessary, therefore, to intercept leakage electromagnetic waves from the cathode ray tube apparatus.
  • shielding is effected using various processes which include electric shielding, electromagnetic shielding, and magnetic shielding.
  • electrostatic shielding process a material with a low electric resistance is used to prevent lines of electric force from leaking out.
  • electromagnetic shielding process a low electric resistance material is used so that a current flow therein can be utilized for shielding.
  • magnetic shielding process a material with a low magnetic resistance is used to confine lines of magnetic force in a shielding conductor.
  • various methods are used including a method in which the deflecting device is covered by means of a metallic plate formed of stainless steel or the like, a method in which the top, bottom, right- and left-side portions, and rear portion of the cathode ray tube apparatus are covered by means of a metallic plate or the like, and a method in which a see-through electromagnetic shielding plate is provided in front of the screen of the cathode ray tube.
  • covering the apparatus by means of a durable metallic plate or forming a film of, e.g., an electrically conductive oxide on the front face of the screen of the cathode ray tube is not an economical method.
  • the object of the present invention is to provide a cathode ray tube apparatus and a cathode ray tube image display apparatus capable of effectively suppressing leakage AC electric fields with ease.
  • a cathode ray tube apparatus which has a deflecting device including a horizontal or vertical deflecting coil for deflecting electron beam for scanning, emitted from an electron gun, the apparatus comprising at least one compensating radiator to which is applied a voltage waveform synchronous with and opposite in polarity to a deflection voltage waveform applied to the horizontal or vertical deflecting coil.
  • a cathode ray tube image display apparatus in which a cathode ray tube apparatus, which has a deflecting device including a horizontal or vertical deflecting coil for deflecting electron beam for scanning, emitted from an electron gun, is set in a cabinet, the image display apparatus comprising at least one compensating radiator to which is applied a voltage waveform synchronous with and opposite in polarity to a deflection voltage waveform applied to the horizontal or vertical deflecting coil.
  • an electric field generated from the compensating radiator is opposite in polarity to the electric field which varies in synchronism with the deflection voltage waveform, so that the two electric fields cancel each other to intercept and suppress a leakage electric field when they are combined with each other.
  • Fig. 2 is a perspective view of a cathode ray tube apparatus according to the present embodiment.
  • This apparatus comprises a cathode ray tube 10, a deflecting device 13, an inverse voltage supply section 14, and compensating electrodes 15.
  • the inverse voltage supply section 14 is used to obtain a voltage opposite in polarity to a deflection voltage applied to the deflecting coils of the deflecting device 13.
  • the compensating radiators or electrodes 15 receive the voltage of the opposite polarity from the supply section 14.
  • the deflection voltage is applied to the input terminal of the inverse voltage supply section 14.
  • One end of an inverse voltage output terminal of the supply section 14 is connected to the radiators 15, and the other end to the ground potential.
  • an external conductive coating 17 and a tension band 18 are connected to the ground potential.
  • the other end of the inverse voltage supply section 14 is connected to the tension band.
  • the cathode ray tube 10 which is constructed in the same manner as the conventional example, mainly comprises a glass envelope formed of a substantially rectangular panel 16 and the funnel 11 continuous therewith, a phosphor screen on the inner surface of the panel 16, and the electron gun in the neck 12 of the funnel 11.
  • the electron gun emits electron beam for exciting the phosphor screen.
  • the deflecting device 13 which is mounted outside the funnel 11, is composed of the horizontal deflecting coil for generating a horizontal deflecting magnetic field, which deflects the electron beam in the horizontal direction, and the vertical deflecting coil for generating a vertical deflecting magnetic field, which deflects the electron beam in the vertical direction.
  • deflecting devices may be classified into two types, a saddle-saddle type and a saddle-toroidal type.
  • the horizontal deflecting coil is formed of a pair of saddle-shaped deflecting coils, upper and lower
  • the vertical deflecting coil is formed of another pair of saddle-shaped deflecting coils, right and left.
  • the horizontal deflecting coil is formed of a pair of saddle-shaped deflecting coils, upper and lower
  • the vertical deflecting coil is formed of a pair of toroidal coils, upper and lower.
  • Voltages of predetermined waveforms which vary in predetermined cycles, are applied individually to the horizontal and vertical deflecting coils, thereby generating deflecting magnetic fields.
  • the voltage applied to the horizontal coil is a pulsating voltage ranging from several hundreds of volts to about 1 kV.
  • the present invention is arranged so that an inverse AC electric field for compensating and suppressing the AC electric field is generated, and these two electric fields are combined to intercept and suppress the AC electric field. The following is a detailed description of an arrangement for this purpose.
  • the apparatus of the present embodiment comprise the inverse voltage supply section 14 and the paired compensating radiators 15, upper and lower (lower one is not shown), arranged near the side wall portion of the panel 16, as shown in Fig. 2.
  • the inverse voltage supply section 14 as shown in Fig. 4, coils 21a and 21b are wound around a ring-shaped core 20, which is a closed magnetic path, and a deflection current flows through the coil 21a.
  • Each end of the coil 21a serves as an input-side terminal.
  • One end 22 of the coils 21b, which constitutes the inverse voltage output terminal, is connected to the compensating radiators 15, and the other end 23 to the ground potential.
  • a magnetic flux is generated in the core 20, and an induced electromotive force is produced in the coil 21b.
  • the direction of the electromotive force in the coil 21b depends on that of the magnetic flux flowing through the core 20. This does not guarantee that the compensating radiators can apply a potential opposite in polarity to the deflection voltage, that is, negative potential, when the deflection voltage is positive.
  • a voltage waveform 24b opposite in polarity to a voltage waveform applied to the coil 21a is applied to the compensating radiators by leading the potential at one output-side end, as a reference potential, to the ground potential.
  • Fig. 4 is an equivalent circuit diagram of this arrangement. In Fig.
  • numeral 30 denotes a main deflecting coil, e.g., the horizontal deflecting coil in the case of the present embodiment.
  • the compensating radiators radiate electric fields which, opposite in polarity to the leakage electric field, vary substantially in synchronism with horizontal deflection.
  • the voltages applied individually to the upper and lower compensating radiators, which are equal in value, are represented by one voltage.
  • Fig. 5 diagrammatically shows an electric field for a certain time, among other AC electric fields generated by the deflecting device of the cathode ray tube apparatus.
  • Fig. 5 is diagrammatic because it illustrates a typical potential distribution formed between the deflecting device and the ground (ground potential) with the electric field approximated simply.
  • equipotential lines 40a spread radially from the center of a deflecting device 41, and the potential becomes lower with distance from the center.
  • Electric force lines 42a are directed radially from the center.
  • FIG. 6 diagrammatically shows an electric field for a certain time, among other AC electric fields generated by upper and lower compensating radiators 43, upper and lower.
  • electric force lines 42b are directed to the compensating radiators in the regions above and below the cathode ray tube apparatus, and to the screen in the region in front of it.
  • Fig. 7 shows a combination of the leakage AC electric field shown in Fig. 5 and the compensatory electric field shown in Fig. 6. As seen from Fig.
  • Figs. 8A, 8B and 8C show potentials on sections A-A', B-B' and C-C' of Figs. 5, 6 and 7, respectively.
  • Each electric field can be calculated as an inclination of each corresponding potential.
  • the electric fields generated from the cathode ray tube apparatus are suppressed.
  • the compensating radiators must be insulated from those portions on the outer surface of the cathode ray tube which are connected to the ground potential for example, outer conductive layer or implosion protection band. The reason is that the compensatory electric field cannot be generated unless the compensating radiators are kept insulated from the portions connected to the ground potential.
  • Figs. 9 to 12 individually show modifications of the compensating electrode according to the present invention.
  • a pair of compensating radiators 61, right and left, are arranged on the side wall of the panel 16 of the cathode ray tube 10.
  • a compensating radiator 62 is arranged throughout the periphery of the side wall of the panel 16 of the cathode ray tube 10.
  • the radiator 62 which may be formed by passing a conductor around the whole periphery of the side wall of panel 16, can enjoy a simple construction.
  • the radiator 62 covers the right- and left-hand side portions of the side wall of the panel 16.
  • radiator 62 It is advisable, in this case, to arrange the radiator 62 so that its potential is uniform throughout the periphery.
  • compensating radiators 63 are arranged individually at the four corners of the panel 10 of the cathode ray tube 10.
  • a compensating radiator 64 is arranged on a screen-side flange portion of the deflecting device 13 of the cathode ray tube apparatus.
  • the compensating electrodes are not limited in shape to the above-described embodiment and modifications, and may alternatively be disk-shaped, rectangular, etc.
  • FIGS. 13A and 13B show the angle dependence of the leakage electric field generated with use of the aforementioned various compensating radiators.
  • FIGs. 13A and 13B show the results of measurement of the leakage AC electric field with the cathode ray tube apparatus of the present invention incorporated in a chassis in a cabinet. It is possible to evaluate an actual use of the cathode ray tube apparatus, when the cathode ray tube is received in the chassis and the leakage AC electric field from the chassis is measured. According to the embodiment and modifications (Figs. 2, 9 and 10) in which the compensating radiator or electrodes are arranged on the front face of the screen, the leakage electric field can be halved. In the case of the compensating radiator 64 of Fig.
  • the same applied voltage for the other compensating radiators is used, so that the amount of suppression of the leakage electric field is small. Since the angle dependence varies depending on the correlation between the location of the compensating radiator and a chassis in the cabinet, which incorporates the cathode ray tube apparatus, the radiator position should preferably be determined as required. If the compensating radiator is located near the deflecting device, the distribution of the compensatory electric field can be approximated to that of the leakage electric field. If the compensating radiator is thus located, however, the inverse potential to be applied to the radiator must be increased substantially to the level of the deflection voltage, which ranges from several hundreds of volts to about 1 kV. In consideration of the dielectric properties, another measure for insulation is needed.
  • the cathode ray tube apparatus is mounted in the chassis, and the leakage electric field can be suppressed to some degree, in all the area except the region in front of the screen, by means of the chassis.
  • a measure to counter the leakage electric field is to suppress the electric field leaked to the front of the screen. Since the voltage to be applied to the compensating radiator can be lowered (substantially to half the deflection voltage or less) as the front face of the screen is approached or with distance from the deflecting device, moreover, the compensating electrode should preferably be situated near the screen.
  • Figs. 14 and 15 individually show modifications of the inverse voltage supply section.
  • the modification shown in Fig. 14 utilizes an induced electromotive force produced by a magnetic flux from a main deflecting magnetic field of a deflecting device 70.
  • the loop plane of coils 72 is positioned in the tube axis direction so that the magnetic flux leaked to the region near a screen-side flange portion 71 of the deflecting device 70 penetrates the loop plane.
  • Leakage magnetic field compensating means 73 are used in the modification shown in Fig. 15.
  • each compensating means 73 is formed of a core 75 wound with a coil 74, through which a current synchronous with a deflection current flows so that a magnetic field directed opposite to the leakage magnetic field is generated.
  • a coil 76 connected to the compensating radiator is wound around the same core 75 having the coil 74 thereon, whereby an induced electromotive force is utilized. In this case, no current flows through the compensating radiators themselves, so that no substantial loss is incurred, and the compensation effect of the leakage magnetic field is lowered by only a small margin. Thus, both the leakage electric field and the leakage magnetic field can be effectively suppressed.
  • the screen front face of the panel need not be provided with any special electromagnetic shielding plate. Accordingly, the screen front face can be furnished with means for non-glare properties or other essential properties without giving consideration to electromagnetic shielding.
  • the leakage electric field should only be suppressed by means of the compensating radiators to which is applied the voltage opposite in polarity to the deflection voltage.
  • the number, location, shape and size of the compensating radiators should be suitably set in consideration of the size of the cathode ray tube apparatus, to which the present invention is applied, the distribution of the leakage electric field, the level of suppression, etc. More specifically, the positional relationships between the compensating radiators and the ground-potential regions should be taken into consideration. Further, the level of the voltage applied to the compensating radiators need not always be equal to that of the deflection voltage, and should only be suitably adjusted depending on the position, length, etc. of the compensating radiators.
  • the applied voltage can be easily adjusted by regulating the number of turns of the coils shown in Fig. 3. Furthermore, different voltages may be applied individually to the upper and lower compensating radiators shown in Fig. 2 or the right- and left-hand compensating radiators shown in Fig. 9.
  • the voltage opposite in polarity to the voltage applied to the horizontal deflecting coil is applied to the compensating radiators, in order to cope with VLF (Very Low Frequency: 2 kHz to 400 kHz) which is attributable to horizontal deflection.
  • VLF Very Low Frequency: 2 kHz to 400 kHz
  • the present invention is not limited to the above embodiment.
  • a voltage opposite in polarity to the voltage applied to the vertical deflecting coil may be applied to the compensating radiators, in order to cope with ELF (Extremely Low Frequency: 5 Hz to 2 kHz) which is attributable to vertical deflection, or independent compensating radiators may be arranged to cope with the VLF and ELF simultaneously.
  • FIG. 16 is a cutaway perspective view of a cathode ray tube image display apparatus according to the present embodiment.
  • a cathode ray tube apparatus 82 is set in a cabinet 81.
  • a compensating radiators 83 are arranged individually at regions near the top and bottom of the side wall of a panel of the cathode ray tube apparatus.
  • a voltage opposite in polarity to the deflection voltage is applied to the electrodes 83.
  • the voltage opposite in polarity to the deflection voltage is applied to the compensating radiators 83 by means of an inverse voltage supply section 84, which is constructed in the same manner as that of the first embodiment shown in Fig. 3.
  • the inverse voltage supply sections shown in Figs. 14 and 15 may be also used for this purpose.
  • a flyback transformer for generating the deflection voltage is provided at the bottom of the cabinet 81.
  • the inverse voltage supply section may be also formed by winding a coil 91 around a flyback core 90, as shown in Fig. 17.
  • a voltage waveform synchronous with and opposite in polarity to the deflection voltage waveform can be obtained directly from a substrate in the cabinet.
  • the compensating radiators may be modified variously, as shown in Figs. 9 to 12 for the first embodiment.
  • the present embodiment is arranged so that the leakage electric field is suppressed by combining an electric field conventionally leaked from the deflecting device of the cathode ray tube apparatus and an electric field generated by means of the compensating radiators to which is applied the voltage opposite in polarity to the deflection voltage. Since the cathode ray tube is set in the cabinet, however, the state of the ground potential is somewhat different from the state for the first embodiment, although there is no difference in basic principle.
  • the compensating radiators are arranged on the side wall of the panel of the cathode ray tube apparatus in the cabinet according to the present embodiment, the invention is not limited to this arrangement.
  • the compensating radiators may be arranged on the inside of the front face of the cabinet, or formed integrally with a degaussing coil which is arranged in a conventional cathode ray tube image display apparatus. It is necessary only that the compensating radiators be located individually in suitable positions for the generation of an inverse electric field which can compensate the leakage electric field.
  • the radiators When arranging the compensating radiators on the inside of the front face of the cabinet, the radiators must only be located on that wall surface of the cabinet which is not in contact with the cathode ray tube apparatus, so that they can be easily insulated from those portions of the apparatus which are connected to the ground potential.
  • the screen front face of the panel need not be provided with any special electromagnetic shielding plate. Accordingly, the screen front face can be furnished with means for non-glare properties or other essential properties without giving consideration to electromagnetic shielding.
  • the leakage electric field should only be suppressed by means of the compensating radiators to which is applied the voltage opposite in polarity to the deflection voltage.
  • the number, location, shape and size of the compensating radiators should be suitably set in consideration of the size of the cathode ray tube image display apparatus, to which the present invention is applied, the distribution of the leakage electric field, the level of suppression, etc. More specifically, the positional relationships between the compensating radiators and the ground-potential regions should be taken into consideration. Further, the level of the voltage applied to the compensating radiators need not always be equal to that of the deflection voltage, and should only be suitably adjusted depending on the position, length, etc. of the compensating radiators.
  • the applied voltage can be easily adjusted by regulating the number of turns of the coils shown in Fig. 3. Furthermore, different voltages may be applied individually to the upper and lower compensating radiators shown in Fig. 2 or the right- and left-hand compensating radiators shown in Fig. 9.
  • the voltage opposite in polarity to the voltage applied to the horizontal deflecting coil is applied to the compensating electrodes, in order to cope with VLF (2 kHz to 400 kHz) which is attributable to horizontal deflection.
  • VLF 2 kHz to 400 kHz
  • the present invention is not limited to the above embodiment.
  • a voltage opposite in polarity to the voltage applied to the vertical deflecting coil may be applied to the compensating electrodes, in order to cope with ELF (5 Hz to 2 kHz) which is attributable to vertical deflection, or independent compensating electrodes may be arranged to cope with the VLF and ELF simultaneously.
  • the leakage electric field can be easily suppressed by arranging at least one compensating radiator to which is applied a voltage waveform synchronous with and opposite in polarity to the deflection voltage waveform.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Details Of Television Scanning (AREA)
EP92112290A 1991-07-18 1992-07-17 Dispositif de tube à rayons cathodique Withdrawn EP0523741A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP177061/91 1991-07-18
JP17706191 1991-07-18

Publications (1)

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EP0523741A1 true EP0523741A1 (fr) 1993-01-20

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EP92112290A Withdrawn EP0523741A1 (fr) 1991-07-18 1992-07-17 Dispositif de tube à rayons cathodique

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EP (1) EP0523741A1 (fr)
KR (1) KR960000350B1 (fr)
CN (1) CN1040934C (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0547856A1 (fr) * 1991-12-14 1993-06-23 Sony Corporation Compensation de champ pour moniteur à tube à rayons cathodiques
EP0565120A1 (fr) * 1992-04-09 1993-10-13 Kabushiki Kaisha Toshiba Tube à rayons cathodiques
EP0568783A1 (fr) * 1992-05-08 1993-11-10 Hitachi, Ltd. Tube à rayons cathodiques avec bobine de déviation
EP0630036A1 (fr) * 1993-06-15 1994-12-21 International Business Machines Corporation Tube à rayons cathodiques avec élimination des émissions de champ électrique
EP0651420A1 (fr) * 1993-10-30 1995-05-03 International Business Machines Corporation Dispositif de réduction de l'émission de champ électrique
EP0702389A2 (fr) 1994-09-15 1996-03-20 International Business Machines Corporation Système de réduction de l'émission de champs électrique
US5561333A (en) * 1993-05-10 1996-10-01 Mti, Inc. Method and apparatus for reducing the intensity of magnetic field emissions from video display units
US5594615A (en) * 1993-05-10 1997-01-14 Mti, Inc. Method and apparatus for reducing the intensity of magenetic field emissions from display device
GB2309367A (en) * 1996-01-18 1997-07-23 Hitachi Media Electron Kk Reducing stray electric fields in displays
GB2309366A (en) * 1996-01-16 1997-07-23 Samsung Electronics Co Ltd Device for cancelling stray electric fields of CRT displays
GB2313279A (en) * 1996-05-13 1997-11-19 Lg Electronics Inc Video display appliance including a device for limiting electric field emitted from a cathode ray tube
EP0821389A2 (fr) * 1996-07-25 1998-01-28 Kabushiki Kaisha Toshiba Tube à rayons cathodiques et appareil de tube à rayons cathodiques
EP0793379A3 (fr) * 1996-02-27 1998-11-18 Totoku Electric Co., Ltd. Procédé pour atténuer le rayonnement de champs électriques d'un dispositif d'affichage avec un tube à rayons cathodiques
US6404133B1 (en) 1999-03-31 2002-06-11 Matsushita Electric Industrial Co., Ltd. Cathode ray tube device that reduces magnetic field leakage

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Publication number Priority date Publication date Assignee Title
GB2223649A (en) * 1988-07-27 1990-04-11 Peter Thompson Wright A screen for an electromagnetic field
EP0415019A1 (fr) * 1989-08-31 1991-03-06 Kabushiki Kaisha Toshiba Dispositif de tube à rayons cathodiques ayant un flux de dispersion magnétique diminué
EP0435602A2 (fr) * 1989-12-23 1991-07-03 Samsung Display Devices Co., Ltd. Bobine de déflexion

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FR2605169B1 (fr) * 1986-10-10 1988-12-09 Radiotechnique Ind & Comm Dispositif de demagnetisation et de mise a la masse pour un tube-image, et machine pour le fabriquer
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Publication number Priority date Publication date Assignee Title
GB2223649A (en) * 1988-07-27 1990-04-11 Peter Thompson Wright A screen for an electromagnetic field
EP0415019A1 (fr) * 1989-08-31 1991-03-06 Kabushiki Kaisha Toshiba Dispositif de tube à rayons cathodiques ayant un flux de dispersion magnétique diminué
EP0435602A2 (fr) * 1989-12-23 1991-07-03 Samsung Display Devices Co., Ltd. Bobine de déflexion

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Title
IBM TECHNICAL DISCLOSURE BULLETIN. vol. 30, no. 12, May 1988, NEW YORK US pages 9 - 10 'Cancellation of leaked magnetic flux' *

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0547856A1 (fr) * 1991-12-14 1993-06-23 Sony Corporation Compensation de champ pour moniteur à tube à rayons cathodiques
US5485056A (en) * 1991-12-14 1996-01-16 Sony Corporation Monitoring device
US5430351A (en) * 1992-04-09 1995-07-04 Kabushiki Kaisha Toshiba Cathode-ray tube apparatus with means for reducing leakage magnetic field
EP0565120A1 (fr) * 1992-04-09 1993-10-13 Kabushiki Kaisha Toshiba Tube à rayons cathodiques
EP0568783A1 (fr) * 1992-05-08 1993-11-10 Hitachi, Ltd. Tube à rayons cathodiques avec bobine de déviation
US5475287A (en) * 1992-05-08 1995-12-12 Hitachi, Ltd. Cathode-ray tube apparatus and yoke
US5594615A (en) * 1993-05-10 1997-01-14 Mti, Inc. Method and apparatus for reducing the intensity of magenetic field emissions from display device
US5561333A (en) * 1993-05-10 1996-10-01 Mti, Inc. Method and apparatus for reducing the intensity of magnetic field emissions from video display units
JPH0720808A (ja) * 1993-06-15 1995-01-24 Internatl Business Mach Corp <Ibm> 電界放射の低減方法及びｃｒｔ表示装置
EP0630036A1 (fr) * 1993-06-15 1994-12-21 International Business Machines Corporation Tube à rayons cathodiques avec élimination des émissions de champ électrique
EP0651420A1 (fr) * 1993-10-30 1995-05-03 International Business Machines Corporation Dispositif de réduction de l'émission de champ électrique
US5432411A (en) * 1993-10-30 1995-07-11 International Business Machines Corporation Electric field emission reduction apparatus
EP0702389A2 (fr) 1994-09-15 1996-03-20 International Business Machines Corporation Système de réduction de l'émission de champs électrique
GB2309366A (en) * 1996-01-16 1997-07-23 Samsung Electronics Co Ltd Device for cancelling stray electric fields of CRT displays
GB2309366B (en) * 1996-01-16 1999-12-29 Samsung Electronics Co Ltd Device for cancelling electric field of display
GB2309367A (en) * 1996-01-18 1997-07-23 Hitachi Media Electron Kk Reducing stray electric fields in displays
GB2309367B (en) * 1996-01-18 1999-12-29 Hitachi Media Electron Kk Display monitor
EP0793379A3 (fr) * 1996-02-27 1998-11-18 Totoku Electric Co., Ltd. Procédé pour atténuer le rayonnement de champs électriques d'un dispositif d'affichage avec un tube à rayons cathodiques
GB2313279A (en) * 1996-05-13 1997-11-19 Lg Electronics Inc Video display appliance including a device for limiting electric field emitted from a cathode ray tube
US5969775A (en) * 1996-05-13 1999-10-19 Lg Electronics, Inc. Video display appliance including a device for eliminating electric field emitted from a cathode ray tube
GB2313279B (en) * 1996-05-13 1998-07-22 Lg Electronics Inc Video display appliance including a device for limiting electric field emitted from a cathode ray tube
EP0821389A3 (fr) * 1996-07-25 1998-12-02 Kabushiki Kaisha Toshiba Tube à rayons cathodiques et appareil de tube à rayons cathodiques
EP0821389A2 (fr) * 1996-07-25 1998-01-28 Kabushiki Kaisha Toshiba Tube à rayons cathodiques et appareil de tube à rayons cathodiques
US6404133B1 (en) 1999-03-31 2002-06-11 Matsushita Electric Industrial Co., Ltd. Cathode ray tube device that reduces magnetic field leakage
US6630791B2 (en) 1999-03-31 2003-10-07 Matsushita Electric Industrial Co., Ltd Cathode ray tube device that reduces magnetic field leakage

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KR960000350B1 (ko) 1996-01-05
KR930003223A (ko) 1993-02-24
CN1069144A (zh) 1993-02-17
CN1040934C (zh) 1998-11-25

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