EP0785566A1 - Kathodenstrahlröhre mit variablem elektrischem Feld und niedriger Strahlung - Google Patents

Kathodenstrahlröhre mit variablem elektrischem Feld und niedriger Strahlung Download PDF

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Publication number
EP0785566A1
EP0785566A1 EP96400129A EP96400129A EP0785566A1 EP 0785566 A1 EP0785566 A1 EP 0785566A1 EP 96400129 A EP96400129 A EP 96400129A EP 96400129 A EP96400129 A EP 96400129A EP 0785566 A1 EP0785566 A1 EP 0785566A1
Authority
EP
European Patent Office
Prior art keywords
crt
electric field
ray tube
cathode ray
conductive material
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Withdrawn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
EP96400129A
Other languages
English (en)
French (fr)
Inventor
Jung-Kun Hsieh
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.)
CAPETRONIC (KAOHSIUNG) CORP
Original Assignee
CAPETRONIC (KAOHSIUNG) 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 CAPETRONIC (KAOHSIUNG) CORP filed Critical CAPETRONIC (KAOHSIUNG) CORP
Priority to EP96400129A priority Critical patent/EP0785566A1/de
Publication of EP0785566A1 publication Critical patent/EP0785566A1/de
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • 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
    • H01J2229/0023—Passive means

Definitions

  • the present invention relates to a CRT, and more specifically to a CRT whereby the peripheral of the screen in contact with the CRT envelope is covered with metallic conductive paint so as to decrease the strength of the varying electric filed and the energy of the non-ionising radiation.
  • TCO Technical Commission
  • the Swedish Confederation of Professional Employees has set certain standards related to monitors and keyboards.
  • One of the requirements is that with the CRT at the first frequency band (5Hz - 2Hz), the electric field, measured 30 cm from the receiving instrument, cannot be higher than 10 V/m.
  • the second frequency band (2KHz - 400KHz) the electric field, measured at 30cm from the receiving instrument, cannot be higher than 1 V/m. Since the public's awareness of safety in the work place is increasing day by day, the standards set by the TCO have been widely accepted by computer manufacturers and soon will be accepted throughout the world.
  • the known technique utilized the addition of eye-protecting type screens to meet the TCO standards, but the costs related to this technique is too high.
  • Figures 1A and 1B show the subject invention having metallic adhesive strips on the CRT.
  • Figure 2 shows a test system for determining whether a given CRT conforms to the TCO standards.
  • Figures 3A and 3B show the test results from the system as shown in Figure 2, measured in the first and second frequency bands for a CRT without metallic adhesive strips.
  • Figures 4A and 4B show the test results, measured with the system as shown in Figure 2 and in the first and second frequency bands for a CRT with the metallic adhesive strips.
  • Figures 1A and 1B show the front and side views of the subject CRT having metallic adhesive strips.
  • the inventor has discovered that if metallic adhesive strips (12) are applied along substantial portions around the periphery of the screen (11) of the CRT (10), e.g. at the outer surface of the CRT, the strength of the electric field and energy of the non-ionising radiation can be decreased to conform to the standards of the TCO.
  • the metal used for the metallic strip is preferably copper or aluminium foil, and the material should cover at least a substantial portion of the contact surface (13) between the screen part (11) and the remainder of the CRT envelope (10).
  • copper or aluminium foil may be replaced by applying metallic conducting paint e.g. on the outer surface of the CRT at the level of the aforementioned contact surface.
  • a 17-inch CRT such as the M41KVZ180 x 11(U) model by Hitachi, is positioned 30 cm from a receiving instrument (21), in accordance to the TCO standards, at the area (22) of receiving signals to test the strength of the electric field and the energy of non-ionising radiation emission from the CRT (20).
  • Figures 3A and 3B show the test results of a CRT without metallic adhesive strips. The tests were conducted by using an oscilloscope probe in the first and second frequency bands. In Figure 3A, at 60Hz (first frequency band), the amplitude is 39 Vp-p (peak-to-peak voltage). In Figure 3B, at 64KHz (second frequency band), the amplitude is 22.3 Vp-p respectively.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
EP96400129A 1996-01-19 1996-01-19 Kathodenstrahlröhre mit variablem elektrischem Feld und niedriger Strahlung Withdrawn EP0785566A1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP96400129A EP0785566A1 (de) 1996-01-19 1996-01-19 Kathodenstrahlröhre mit variablem elektrischem Feld und niedriger Strahlung

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP96400129A EP0785566A1 (de) 1996-01-19 1996-01-19 Kathodenstrahlröhre mit variablem elektrischem Feld und niedriger Strahlung

Publications (1)

Publication Number Publication Date
EP0785566A1 true EP0785566A1 (de) 1997-07-23

Family

ID=8225215

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96400129A Withdrawn EP0785566A1 (de) 1996-01-19 1996-01-19 Kathodenstrahlröhre mit variablem elektrischem Feld und niedriger Strahlung

Country Status (1)

Country Link
EP (1) EP0785566A1 (de)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0179298A1 (de) * 1984-10-09 1986-04-30 Viggo Berthelsen Verfahren zur Eliminierung des Einflusses einer Magnetfeldquelle auf eine oder mehrere Personen oder Tiere und eine Vorrichtung zur Eliminierung solcher Einflüsse
WO1991015869A1 (en) * 1990-04-10 1991-10-17 Fribab Ab A device for reducing the field effect from tv screens
DE4123565C1 (de) * 1991-07-16 1992-09-17 Tandberg Data A/S, Oslo, No
EP0547856A1 (de) * 1991-12-14 1993-06-23 Sony Corporation Feldkompensation für Kathodenstrahlröhremonitor
DE4330952A1 (de) * 1992-09-09 1994-03-10 Mitsubishi Electric Corp Kathodenstrahlröhren-Anordnung

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0179298A1 (de) * 1984-10-09 1986-04-30 Viggo Berthelsen Verfahren zur Eliminierung des Einflusses einer Magnetfeldquelle auf eine oder mehrere Personen oder Tiere und eine Vorrichtung zur Eliminierung solcher Einflüsse
WO1991015869A1 (en) * 1990-04-10 1991-10-17 Fribab Ab A device for reducing the field effect from tv screens
DE4123565C1 (de) * 1991-07-16 1992-09-17 Tandberg Data A/S, Oslo, No
EP0547856A1 (de) * 1991-12-14 1993-06-23 Sony Corporation Feldkompensation für Kathodenstrahlröhremonitor
DE4330952A1 (de) * 1992-09-09 1994-03-10 Mitsubishi Electric Corp Kathodenstrahlröhren-Anordnung

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