EP0571206A1 - Kathodenstrahlröhre - Google Patents

Kathodenstrahlröhre Download PDF

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Publication number
EP0571206A1
EP0571206A1 EP93303915A EP93303915A EP0571206A1 EP 0571206 A1 EP0571206 A1 EP 0571206A1 EP 93303915 A EP93303915 A EP 93303915A EP 93303915 A EP93303915 A EP 93303915A EP 0571206 A1 EP0571206 A1 EP 0571206A1
Authority
EP
European Patent Office
Prior art keywords
panel
axis
shadow
screen
grid
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Withdrawn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
EP93303915A
Other languages
English (en)
French (fr)
Inventor
Seong-Keun Park
Jong-Yeob Sa
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.)
Samsung SDI Co Ltd
Original Assignee
Samsung Display Devices Co Ltd
Samsung Electron Devices Co Ltd
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
Priority claimed from KR1019920008572A external-priority patent/KR930024073A/ko
Priority claimed from KR1019930005993A external-priority patent/KR0135858B1/ko
Application filed by Samsung Display Devices Co Ltd, Samsung Electron Devices Co Ltd filed Critical Samsung Display Devices Co Ltd
Publication of EP0571206A1 publication Critical patent/EP0571206A1/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Withdrawn legal-status Critical Current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
    • H01J29/86—Vessels; Containers; Vacuum locks
    • H01J29/861—Vessels or containers characterised by the form or the structure thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/86—Vessels and containers
    • H01J2229/8613—Faceplates
    • H01J2229/8616—Faceplates characterised by shape
    • H01J2229/862—Parameterised shape, e.g. expression, relationship or equation

Definitions

  • the present invention relates to a cathode ray tube, and particularly to a cathode ray tube in which the curvature of the outer surface of a panel is improved so as to prevent the distortion of an image formed on a screen.
  • a cathode ray tube (CRT) is constructed to have a panel 11 on the inner surface of which a phosphor screen 11a is formed, and a funnel 12 which is attached to the panel.
  • Funnel 12 includes a neck 12 housing an electron gun 13, and a deflection yoke 14 is installed outside the neck.
  • a shadow mask 15 is mounted on the inner side of panel 11, while being detached from screen 11a by a predetermined distance.
  • an electron beam emitted from electron gun 13 installed in neck 12a of funnel 12 is deflected by deflection yoke 14 and, as shown in Fig.2, is projected in the horizontal direction of phosphor screen 11a (which is the longer axis X-X) and in the vertical direction of the phosphor screen (which is the shorter axis Y-Y).
  • Such two-dimensional projection forms a raster on phosphor screen 11a.
  • the outer surface of the panel of the CRT has a predetermined radius of curvature, and when a picture formed on phosphor screen 11a of the panel is viewed from the side thereof, the picture formed on the periphery of phosphor screen 11a is seen as distorted. Thus, the viewer does not experience a sense of flatness.
  • the panel has been attempted to be formed flat.
  • This involves these problems: first, the structural strength of the CRT is difficult to maintain, owing to the vacuum pressure acting on its interior; secondly, when the picture formed on the phosphor screen is viewed from the side, the central portion of the picture appears concave; and thirdly, since the shadow mask is locally heated and therefore thermally expanded due to the electron beam emitted from the electron gun, the electron beam cannot precisely land on the phosphor screen, thereby creating a color blurring phenomenon.
  • the diagonal curvature of the outer surface of the panel is expressed as a quadratic function.
  • the curvature according to the quadratic function has a portion in which the quadratic function has a negative value so as to accomplish flatness in the corners of the panel.
  • such a panel exhibits certain problems.
  • the design of the curvature contour of the outer surface of the panel produces the problem of external-light reflection on the outer surface of the panel. Particularly, since the inflection point is placed in the corners of the panel, the peripheral light irradiated onto the outer surface of the panel is scattered.
  • a grid 100 was installed to be detached from the outer surface of the panel which is opposite to phosphor screen 11a, by a predetermined distance (about 2m).
  • a light source 110 located above grid 100 the pattern of the grid was projected onto the outer surface of the panel so as to analogically interpret the degree of deformation of a picture according to the degree of deformation of the projected shadow of grid 100.
  • a cathode ray tube having a panel wherein a grid is installed so as to be detached from the panel by a predetermined distance and a light source is installed in front of the grid, in which, with X representing the longer axis of the panel and Y representing the shorter axis of the panel, the radii of the curvatures of the X and Y axes are each less than seven times the radius of the curvature of the panel, and the radius of the curvature of the panel is equal to the effective diagonal times 1.167 while satisfying the inequalities -0.01 ⁇ ⁇ Y/L x ⁇ 0.01 and -0.01 ⁇ ⁇ X/L Y ⁇ 0.01 where ⁇ X is the degree of distortion of the shadow of the light source projected onto the panel's outer surface, with respect to its horizontal axis; ⁇ Y is the degree of distortion of the shadow of the light source projected onto the panel's outer surface, with respect to its vertical axis; L X is the horizontal length of the panel
  • Fig.1 is a cross-sectional view of a general CRT.
  • Fig.2 is a frontal view of the panel of the CRT shown in Fig.1.
  • Fig.3 is a perspective view of an apparatus for projecting the shadow of a grid onto the outer surface of the panel of a CRT.
  • Figs.4 and 5 are plan views showing the distortion state of a picture formed on the screen of a conventional CRT.
  • Figs.6-23 are plan views for showing the shadow patterns formed by projecting a grid onto the outer surface of the panel of a CRT, according to various panel curvatures.
  • Fig.24 is a plan view for showing the length of the longer axis of the panel versus that of the shorter axis and the degree of distortion of the shadow pattern of a grid projected onto the outer surface of the panel of a CRT according to the present invention.
  • a general cathode ray tube is constructed to have a panel on the inner surface of which a phosphor screen is formed, and a funnel which is attached to the panel.
  • the funnel includes a neck housing an electron gun, and a deflection yoke installed outside the neck.
  • the curvature equation of the outer surface of the panel is expressed as the following approximate equation by combining the elements of quadratic and biquadratic equations while considering the axis symmetry:
  • Z A1X2 + A2X4 + A3Y2 + A4Y4 + A5X2Y2 + A6X4Y2 + A7X2Y4 + A8X4Y4
  • Figs.6-24 illustrate the results of simulations of the shadow patterns formed by projecting the grid net onto the panel, the curvature of which is obtained by varying the coefficients of equation (1).
  • the distortion of the shadow projected onto the outer surface of the panel is completely removed as shown in Fig.7, so that the picture formed on the phosphor screen of the panel is not distorted when the television screen is viewed from any direction.
  • the pattern of the grid projected on the outer surface of the panel is slightly distorted in the pincushion shape on the periphery of the panel as shown in Fig.8, so that the picture formed on the phosphor screen is distorted on the periphery of the panel.
  • the pattern of the grid projected onto the outer surface of the panel is distorted in the pincushion shape as shown in Fig.10.
  • the picture formed on the phosphor screen is distorted on the periphery of the panel and interference of the picture due to external light appears slightly on the periphery of the panel.
  • the pattern of the shadow projected onto the outer surface of the panel becomes the pincushion shape throughout the outer surface while excluding the central portion of the panel as shown in Fig. 11. Accordingly, the picture formed on the phosphor screen appears distorted throughout the outer surface while excluding the central portion.
  • the shadow of the grid projected onto the outer surface of the panel is distorted in the barrel shape on the periphery of the outer surface of the panel as shown in Fig.l3, so that the periphery of the picture formed on the phosphor screen would be distorted.
  • the pattern of shadow projected onto the outer surface of the panel becomes the pincushion shape throughout the outer surface excluding the central portion of the panel as shown in Fig.16.
  • the shadow projected onto the outer surface of the panel is distorted in the barrel shape on the periphery of the outer surface of the panel as shown in Fig.17.
  • the pattern of the grid projected onto the outer surface of the panel is distorted in the pincushion shape on the periphery of the panel, as shown in Fig.20.
  • the pattern of the shadow projected onto the outer surface of the panel becomes the pincushion shape throughout the outer surface while excluding the central portion of the panel, as shown in Fig.21.
  • the shadow projected onto the outer surface of the panel is distorted in the barrel shape on the periphery of the outer surface of the panel as shown in Fig.22.
  • the inventor found that, when the length ratio of the longer axis to the shorter axis of the panel and the distortion amount of the shadow pattern formed by projecting grid 100 (as shown in Fig.3) onto the outer surface of the panel in which, given the radius R of the curvature of a panel to be the length of the effective diagonal times 1.167, the radii of the curvatures of the X and Y axes are each less than seven times the radius R, were within a predetermined range, the picture formed on the phosphor screen was not distorted even if the outer surface of the panel is formed as curved and the external light did not interfere in the picture.
  • the outer surface of the panel has a curvature in which the shadow pattern formed by projecting the latticed-shape grid is not distorted, so that, when a picture formed on the phosphor screen of the panel is viewed from any direction, the picture formed thereon is not distorted and the external light does not interfere in the picture.

Landscapes

  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
EP93303915A 1992-05-20 1993-05-20 Kathodenstrahlröhre Withdrawn EP0571206A1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR1019920008572A KR930024073A (ko) 1992-05-20 음극선관용 패널
KR857292 1992-05-20
KR1019930005993A KR0135858B1 (ko) 1993-04-09 1993-04-09 스크린면의 곡률이 개선된 음극선관
KR599393 1993-04-09

Publications (1)

Publication Number Publication Date
EP0571206A1 true EP0571206A1 (de) 1993-11-24

Family

ID=26629073

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93303915A Withdrawn EP0571206A1 (de) 1992-05-20 1993-05-20 Kathodenstrahlröhre

Country Status (2)

Country Link
EP (1) EP0571206A1 (de)
JP (1) JPH06103926A (de)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0283129A2 (de) * 1987-03-20 1988-09-21 Hitachi, Ltd. Farbbildröhre mit Schattenmaske
EP0438197A1 (de) * 1990-01-17 1991-07-24 Koninklijke Philips Electronics N.V. Elektronenstrahlröhre mit gekrümmtem Bildfenster und Farbbildwiedergabeanordnung
EP0448401A2 (de) * 1990-03-22 1991-09-25 Matsushita Electronics Corporation Kathodenstrahlröhre mit Schattenmaske

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2680021B2 (ja) * 1988-03-16 1997-11-19 株式会社日立製作所 シャドウマスク形カラーブラウン管

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0283129A2 (de) * 1987-03-20 1988-09-21 Hitachi, Ltd. Farbbildröhre mit Schattenmaske
EP0438197A1 (de) * 1990-01-17 1991-07-24 Koninklijke Philips Electronics N.V. Elektronenstrahlröhre mit gekrümmtem Bildfenster und Farbbildwiedergabeanordnung
EP0448401A2 (de) * 1990-03-22 1991-09-25 Matsushita Electronics Corporation Kathodenstrahlröhre mit Schattenmaske

Also Published As

Publication number Publication date
JPH06103926A (ja) 1994-04-15

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Owner name: SAMSUNG DISPLAY DEVICES CO., LTD.

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Effective date: 19931111

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Effective date: 19951128

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Effective date: 19960410