WO2000079562A1 - Color display device having quadrupole convergence coils - Google Patents
Color display device having quadrupole convergence coils Download PDFInfo
- Publication number
- WO2000079562A1 WO2000079562A1 PCT/EP2000/005710 EP0005710W WO0079562A1 WO 2000079562 A1 WO2000079562 A1 WO 2000079562A1 EP 0005710 W EP0005710 W EP 0005710W WO 0079562 A1 WO0079562 A1 WO 0079562A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- winding
- coils
- convergence
- display device
- color display
- Prior art date
Links
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
- H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
- H01J29/48—Electron guns
- H01J29/51—Arrangements for controlling convergence of a plurality of beams by means of electric field only
-
- 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
- H01J29/701—Systems for correcting deviation or convergence of a plurality of beams by means of magnetic fields at least
- H01J29/702—Convergence correction arrangements therefor
- H01J29/705—Dynamic convergence systems
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/236—Manufacture of magnetic deflecting devices for cathode-ray tubes
Definitions
- the invention relates to a color display device comprising an in-line electron gun for generating three electron beams, and a unit for deflecting the electron beams across the color selection electrode.
- Such display devices are known.
- a present aim is to make the outer surface of the display window flatter, so that the image represented by the color display device is perceived by the viewer as flat.
- the radius of curvature of the inner surface of the display window and of the color selection electrode should increase, and, as the color selection electrode becomes flatter, the strength of the color selection electrode decreases and hence the sensitivity to doming and vibrations increases.
- An alternative solution to this problem would be to curve the inner surface of the display window more strongly than the outer surface.
- a color selection electrode having a relatively small radius of curvature can be used. As a result, doming and vibration problems are reduced, however other problems occur instead.
- the thickness of the display window is much larger at the edges than in the center. As a result, the weight of the display window increases and the intensity of the image decreases substantially towards the edges.
- EP 0,421,523 discloses a color cathode ray tube with an in-line gun, a pin cushion correcting yoke and an eyebrow effect electronoptical distortion correction device comprising two pairs of coils, each pair having a coil on each outer electron beam side of the neck in the plane of the beams.
- the coil pairs are spaced apart along the Z-axis between the gun and the yoke and are driven by a sawtooth current having a bow-tie envelope synchronous with the raster scan to correct the dynamic, -intisymmetrical eyebrow effect apparent as a purity defect on the raster.
- WO 99/34392 describes a color display device comprising a color cathode ray tube including an in-line electron gun for generating three electron beams being located substantially within a plane extending in an X-direction of a rectangular X-Z coordinate system, a color selection electrode, deflecting means for deflecting the electron beams located at a deflection plane, and first and second influencing means to dynamically influence the convergence of the electron beams, to decrease a distance between the electron beams at a location of the deflection plane.
- WO 99/34392 describes many different ways in which the influencing means may be embodied. One of the possibilities mentioned is to integrate the second influencing means with the deflection unit.
- the second influencing means may be embodied as four coils, which generate a magnetic quadrupole field.
- the invention provides a color display device, a deflection unit and a method of manufacturing such a color display device as defined in the independent claims.
- the dependent claims describe advantageous embodiments.
- Fig. 1 is a sectional view of a display device, in which the invention is schematically shown;
- Figs. 2 A, 2B show embodiments of the second influencing means according to the invention
- Figs. 3 A, 3B show a first and a second part of the ring-shaped element according to an embodiment of the invention
- Fig. 4 shows a deflection unit according to an embodiment of the invention.
- Fig. 5 shows a further embodiment of the invention.
- the display device shown in Fig. 1 comprises a cathode ray tube, in this example a color display tube, having an evacuated envelope 1 which includes a display window 2, a cone portion 3 and a neck 4.
- an in-line electron gun 5 for generating three electron beams 6, 7 and 8 which extend in one plane, the in-line plane, extending in an X-direction of a rectangular coordinate system.
- the central electron beam 7 substantially coincides with the tube axis 9, which extends in the Z-direction.
- a third direction, the Y-direction extends in a direction perpendicularly to the in-line plane (not shown in the Figure).
- the tube is positioned such that the X-Z plane coincides with a horizontal plane and the Y- direction coincides with a vertical direction.
- the inner surface of the display window is provided with a display screen 10.
- the display screen 10 comprises a large number of phosphor elements luminescing in red, green and blue.
- the electron beams are deflected across the display screen by way of an electromagnetic deflection unit 51 and pass through a color selection electrode 11 which is arranged in front of the display window 2 and which comprises a thin plate having apertures 12.
- the three electron beams 6, 7 and 8 pass through the apertures 12 of the color selection electrode at a small angle relative to each other and hence each electron beam impinges only on phosphor elements of one color.
- the deflection unit 51 comprises, in addition to a coil holder 13, deflection coils 13' for deflecting the electron beams in two mutually perpendicular directions.
- the display device further includes means for generating voltages, which during operation are fed to components of the electron gun via feedthroughs.
- the deflection plane 20 is schematically indicated as well as the distance p between the electron beams 6 and 8 in this plane, and the distance q between the color selection electrode and the display screen. The distance q is inversely proportional to the distance p.
- the color display device comprises two electron beam convergence influencing units 14, 14', whereby a first unit 14 is used, in operation, to dynamically bend, i.e. as a function of the deflection in a direction, the outermost electron beams towards each other, and a second unit 14' serves to dynamically bend the outermost electron beams in opposite directions.
- the two units 14, 14' are positioned at some distance from each other, and are used to vary the distance p, as a function of the deflection, in a such a manner that the distance p decreases as a function of the deflection in at least one direction.
- the first unit 14 is positioned close to the gun and will be referred to as the "gun quadrupole", whereas the second unit 14' is located near the deflection unit and will be referred to as the "yoke quadrupole".
- the means 14' (“the yoke ring quadrupole") then is obtained by making the coils 22' from electrically conductive wires, which are toroidally wound in a winding direction and according to a winding density distribution N ( ⁇ ) given by
- N ( ⁇ ) N 0 cos (2 ⁇ ) + C; where ⁇ is an angle enclosed by the X-direction and a line between an element of the coil and the center, which ranges between 0° and 360°, N 0 is the winding density at ⁇ equal to 0°, the sign of N ( ⁇ ) denotes the winding direction and C is a constant.
- This embodiment has the advantage that an almost pure quadrupole field can be generated, i.e. the presence of other magnetic multiple fields is largely suppressed.
- FIGs. 2A and 2B An embodiment of such an approximation is shown in Figs. 2A and 2B, for the situation that the constant C is taken equal to zero.
- This embodiment comprises packages 30 of electrically conductive wires, which are toroidally wound around a yoke ring 21 ' according to the above winding density
- windings have been made in grooves 34 of yoke ring 21' that are spaced 15 degrees apart.
- N ( ⁇ )
- the coil thus comprises only two packages of windings, in stead of four packages.
- the yoke ring can be split for reasons of coil winding and/or yoke ring assembly.
- double saddle yokes where the ends of the coils that are located at the gun side, have a diameter larger than the inner diameter of the yoke ring, may be used. Since for such saddle yokes it is necessary to be able to split the yoke ring during yoke assembly. Furthermore, the occurrence of significant line frequent voltages can be avoided by winding the two packages individually in layers. This is effective since the line flux changes sign at the top and bottom of the yoke -ring.
- Figs. 3 A and 3B show an embodiment of the invention.
- Fig. 3 A shows a first part 60 of the ring-shaped element 21 ', which part is most close to the electron gun 5.
- the first part has been provided with rings 60,66 having grooves into which the coil windings are positioned.
- Fig. 3B shows a second part 68 of the ring-shaped element 21 ', which part is closest to the display window 2.
- the two parts 60,68 may be connected to each other by any conventional connection means, such as glue, tape or the like. Connection of the two parts is not essential for a proper performance.
- This embodiment of the invention has the advantage that it reduces the influence of the means 14' on certain image artifacts.
- certain image artifacts such as East- West pincushion raster distortion and an over-correction of non-linearities in the electron beam deflection may occur.
- the inventors have realized that this influence may be reduced by splitting the ring-shaped element 21 ' into two parts 60,68. A first part 60 being positioned closer to the in-line gun 5 than a second part 68, and the first 60 and/or the second 68 part having the four coils 22'.
- the quadrupole coil is wound around the core part closest to the gun.
- Fig. 4 shows the two parts 60,68 according to the invention when positioned around the deflection coils 13' and the coil holder 13.
- the first part 60 has been provided with rings 60,66 and four coils 22' for generating the magnetic quadrupole field.
- Fig. 5 a further embodiment of the invention is shown.
- the magnetic quadrupole field can simply be generated by the field coil set 70 itself, without the use of any additional coils. This is realized as follows: to the field coil set, in addition to the normal field signal for the electron deflection, an additional signal is added. This additional signal is then used for generating the quadrupole field via the field coil set.
- the field coil set 70 comprising two coils, is fed with input signals 72, 74 of 2 Ampere.
- the signal for the quadrupole field 76 having, for example, a value of 1 Ampere, is added to the input signals 72, 74 via the asymmetrically driving means 80 to result into two asymmetrical driving signals having values of 3 and 1 Ampere, respectively. These asymmetrical signals are then fed to the two coils of the field coil set 70, which results in the magnetic field for the deflection of the electrons and the quadrupole field.
- the asymmetrically driving means 80 can be of the form of any conventional means within the reach of a person skilled in the art. For example, a set of two diodes properly positioned between the coils and the input signals 72, 74 may do.
- a preferred method of manufacturing the second convergence unit 14' (“the yoke ring quadrupole"), where the coils 22' comprise layers, comprises the steps of: providing a ring-shaped element 21' and winding electrically conductive wire toroidally around the ring-shaped element 21'.
- the winding step comprises of a first step winding a first layer of each of the coils, and at least one further step, of winding a further layer of each of the coils.
- This method of winding the second convergence unit is different from a simpler method in which the coils are wound in one layer.
- the simpler method may cause ringing problems as well as reliability problems. Ringing is an unwanted inductive interference phenomenon between line and frame coils 13' of the deflection unit 51.
- the preferred method of winding according to the invention is visible by the many interconnection wires between the four coils 22.
- a preferred embodiment of the invention relates to a color display device comprising an in-line electron gun 5 for generating three electron beams 6,7,8, and a convergence unit 14' to dynamically influence the convergence of the electron beams, to decrease a distance p between the electron beams.
- the convergence unit 14' comprises a ring-shaped element 21' having four coils 22'.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Video Image Reproduction Devices For Color Tv Systems (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020017002121A KR20010099625A (en) | 1999-06-22 | 2000-06-21 | Color display device having quadrupole convergence coils |
US09/763,303 US6608436B1 (en) | 1998-12-22 | 2000-06-21 | Color display device having quadrupole convergence coils |
JP2001505036A JP2003529893A (en) | 1999-06-22 | 2000-06-21 | Color display device having quadrupole convergence coil |
EP00943845A EP1105912A1 (en) | 1999-06-22 | 2000-06-21 | Color display device having quadrupole convergence coils |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/338,049 | 1999-06-22 | ||
US09/338,049 US6411027B1 (en) | 1997-12-29 | 1999-06-22 | Color display device having quadrupole convergence coils |
EP00201507 | 2000-04-27 | ||
EP00201507.1 | 2000-04-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2000079562A1 true WO2000079562A1 (en) | 2000-12-28 |
Family
ID=26072178
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2000/005710 WO2000079562A1 (en) | 1998-12-22 | 2000-06-21 | Color display device having quadrupole convergence coils |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1105912A1 (en) |
JP (1) | JP2003529893A (en) |
KR (1) | KR20010099625A (en) |
CN (1) | CN1315052A (en) |
WO (1) | WO2000079562A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1298697A2 (en) * | 2001-10-01 | 2003-04-02 | Matsushita Electric Industrial Co., Ltd. | Cathode-ray tube device |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4117434A (en) * | 1977-01-19 | 1978-09-26 | General Electric Company | Hybrid deflection system with quadripolar correction coils |
JPS5815384A (en) * | 1981-07-21 | 1983-01-28 | Mitsubishi Electric Corp | Color picture tube |
EP0073005A2 (en) * | 1981-08-18 | 1983-03-02 | Mitsubishi Denki Kabushiki Kaisha | Color cathode ray tube device |
EP0421523A1 (en) * | 1989-10-02 | 1991-04-10 | Koninklijke Philips Electronics N.V. | Colour display tube system with reduced spot growth |
WO1992002033A1 (en) * | 1990-07-19 | 1992-02-06 | Rca Licensing Corporation | A deflection system with a pair of quadrupole arrangements |
US5565732A (en) * | 1991-04-02 | 1996-10-15 | U.S. Philips Corporation | Color display tube system with reduced spot growth |
WO1999034392A1 (en) * | 1997-12-29 | 1999-07-08 | Koninklijke Philips Electronics N.V. | Color display device with a deflection-dependent distance between outer beams |
-
2000
- 2000-06-21 EP EP00943845A patent/EP1105912A1/en not_active Withdrawn
- 2000-06-21 JP JP2001505036A patent/JP2003529893A/en active Pending
- 2000-06-21 CN CN00801158A patent/CN1315052A/en active Pending
- 2000-06-21 KR KR1020017002121A patent/KR20010099625A/en not_active Application Discontinuation
- 2000-06-21 WO PCT/EP2000/005710 patent/WO2000079562A1/en not_active Application Discontinuation
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4117434A (en) * | 1977-01-19 | 1978-09-26 | General Electric Company | Hybrid deflection system with quadripolar correction coils |
JPS5815384A (en) * | 1981-07-21 | 1983-01-28 | Mitsubishi Electric Corp | Color picture tube |
EP0073005A2 (en) * | 1981-08-18 | 1983-03-02 | Mitsubishi Denki Kabushiki Kaisha | Color cathode ray tube device |
EP0421523A1 (en) * | 1989-10-02 | 1991-04-10 | Koninklijke Philips Electronics N.V. | Colour display tube system with reduced spot growth |
WO1992002033A1 (en) * | 1990-07-19 | 1992-02-06 | Rca Licensing Corporation | A deflection system with a pair of quadrupole arrangements |
US5565732A (en) * | 1991-04-02 | 1996-10-15 | U.S. Philips Corporation | Color display tube system with reduced spot growth |
WO1999034392A1 (en) * | 1997-12-29 | 1999-07-08 | Koninklijke Philips Electronics N.V. | Color display device with a deflection-dependent distance between outer beams |
Non-Patent Citations (1)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 007, no. 088 (E - 170) 12 April 1983 (1983-04-12) * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1298697A2 (en) * | 2001-10-01 | 2003-04-02 | Matsushita Electric Industrial Co., Ltd. | Cathode-ray tube device |
EP1298697A3 (en) * | 2001-10-01 | 2004-07-28 | Matsushita Electric Industrial Co., Ltd. | Cathode-ray tube device |
Also Published As
Publication number | Publication date |
---|---|
EP1105912A1 (en) | 2001-06-13 |
KR20010099625A (en) | 2001-11-09 |
CN1315052A (en) | 2001-09-26 |
JP2003529893A (en) | 2003-10-07 |
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