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
  • H01J29/70—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
  • H01J29/703—Static convergence systems
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
  • H01H13/02—Details
  • H01H13/12—Movable parts; Contacts mounted thereon
  • H01H13/14—Operating parts, e.g. push-button
  • H01H13/16—Operating parts, e.g. push-button adapted for operation by a part of the human body other than the hand, e.g. by foot
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H3/00—Mechanisms for operating contacts
  • H01H3/02—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch
  • H01H3/14—Operating parts, i.e. for operating driving mechanism by a mechanical force external to the switch adapted for operation by a part of the human body other than the hand, e.g. by foot
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H2231/00—Applications
  • H01H2231/008—Video game

Definitions

• the present invention relates to a convergence device for a color picture tube.
• a color picture tube for embodying a color image can be classified as an aperture alternately exciting R(Red), G(Green), and B(Blue) phospors by a single beam, a trio type where three electron guns are arranged independently, and an in-line type where three electron guns are arranged horizontally.
• the in-line type color picture tube comprises the electron gun assembly formed of three electron guns horizontally arranged in parallel. Referring to FIG. 1 , after electron beams emitted from the electron guns 10 that are composed of a plurality of electrodes G1 ,-,Gm are collected and accelerated, they are made to successively scan each position on a screen S by a deflection unit DY.
• each electron beam should converge to a point (in reality, a position on a corresponding phospor in a pixel, i.e., three phospor points in one pixel on the screen S), and this is called a converged state.
• the electron gun is formed of a plurality of electrodes G1 and G2, and if each electrode G1 and G2 is precisely assembled, then the electron beams 20 are emitted through a hole and land normally on the screen. But in general, each hole for the electron beams is not on the same axis and tend to be deflected due to manufacturing error of the electrodes G1 and G2 and assembling error of the electron guns. This blocks the passage of the electron beam 20 and the image landing on the screen becomes blurred (image spreading), the brightness lowers( the brightness and the contrast become low), and colors appear less pure 5 (lowering in the purity of colors).
• a plurality of magnetic ring pairs are installed at a holder H that is installed around the neck of a picture tube T, as shown in FIG. 1 , and control the convergence of the electron beam 20.
• magnetic rings 30 constituting each pair are composed of a plurality of poles (N and S) such as 2, 4, 6 or 8 poles per pair, by making a ring type magnetic material, as shown in FIG. 8(A), have different magnetism at different parts of the ring.
• Such ring type pairs (P2, P4, P6) are used in almost all color picture 5 tubes for adjusting the convergence, but due to the characteristics of the construction, they are only suitable for fine adjustment but cause an interference problem when the degree of adjustment becomes large.
• the magnetic force of each pole N and S
• each magnet should be o magnetized by a stronger magnetic flux density.
• other electron beams as well as the electron beam whose path is desired to be adjusted are affected so that interference phenomena occur, and it thus becomes difficult to properly adjust the paths of the electron beams to achieve the convergence.
• Such problems are becoming 5 more serious with respect to recent technology which expands the horizontal separation distance between electron beams, that is OCV (Outer Convergence Valence), for compensating for heat drift .
• OCV Outer Convergence Valence
• Such problems are due to the excessive expansion of a line of magnetic force formed between opposite magnetic poles (N and S).
• the outside is magnetized to be an N pole and the inside to be an S pole in the top area, and the outside is magnetized to be an S pole and the inside to be an N pole in the bottom area, thus forming a magnetic field between the N and S poles inside.
• a high magnetic flux density is formed between the inside and outside of the magnetized part of each pole (N and S).
• the magnetic flux formed in the space between separate poles (N and S) has a relatively low magnetic flux density, and expands to a wide range.
• a convergence device of the present invention is characterized in that the convergence device is equipped with a block magnet that is composed of a single magnet and a loading means for supporting the block magnet to be disposed at a predetermined position on a path encircling the paths of electron beams and for guiding the block magnet in the radial direction.
• FIG. 1 is a schematic cross-sectional diagram illustrating the construction of an in-line type color picture tube.
• FIGS. 2A through 2F are schematic cross-sectional diagrams illustrating various convergence devices of the present invention.
• FIG. 3 is a schematic cross-sectional diagram illustrating another construction of a convergence device of the present invention.
• FIGS. 4A through 4C are schematic cross-sectional diagrams for explaining an image spreading phenomenon due to a deflection of electron beam and the operation principle of the present invention.
• FIGS. 5A and 5B are a top view and a side view of an assistant holder for loading a convergence device of the present invention, respectively.
• FIGS. 6A and 6B are a top view and a side view of a loaded state of a block magnet, respectively.
• FIGS. 7A and 7B are vop views illustrating a preferred embodiment of a block magnet for use in the present invention.
• FIGS. 8A and 8B show lines of magnetic force for explaining the principle of the present invention in comparison with the conventional construction.
• FIGS. 9A through 9L show lines of magnetic force for explaining various methods of using and operating the present invention.
• FIGS. 10A and 10B show lines of magnetic force that illustrate other methods of using the present invention.
• FIGS. HA through 11 C show lines of magnetic force that illustrate the operation principle of the present invention.
• FIGS. 12A and 12B show lines of magnetic force illustrating the principle that the movement distance of each of three electron beams is different when the magnetic force of a block magnet is large.
• a convergence device includes one or both of block magnets F2P and F2P', which are substituted for the conventional 2 pole pair and are installed in respective assistant holders 1 and 1 ' on a holder H that is loaded on the neck of a picture tube together with the 4 and 6 holes pairs p4 and p6.
• the 2 pole pair moves three electron beams for exciting R, G and B phospors in the same direction
• the 4 pole pair P4 moves the outside beams (R and B) in the opposite direction, including rotation
• the 6 pole pair moves the outsides beams (R and B) in the same direction.
• the block magnet F2p is substituted for the conventional 2 pole pair. But as described later, it can be of course substituted for a 4, 6, 8, or more pole pair according to the construction. For example, in the embodiment of FIG. 3, it is substituted for the 4 pole pair.
• the magnetic flux formed by the block magnet F2p is formed not between the poles N and S of two magnets that are separated in space, but between the magnetic poles N and S of the same block magnet F2p. Accordingly, the effective range of the magnetic field and interference is limited to the region nearthe block magnet F2p and the magnetic flux density becomes very high.
• the method of adjusting the convergence with a convergence device of such construction is a linear method where the block magnet F2p is directly advanced toward and retracted from the electron beam 20 within the desired region.
• the convergence device of the present invention is equipped with the assistant holder 1 as a loading means of the block magnet F2p shown in FIGS. 5 and 6.
• the assistant holder 1 is an approximate ring-type for being loaded on the holder H of the convergence device and is equipped with a plurality of loading holes 2 for support and guidance of the block magnet F2p at a plurality of positions on the outer circumference and a protruding part for tension action.
• the shown assistant holder 1 is equipped with 4 loading holes 2 arranged in a cross (+) formation, and a block magnet F2p can be loaded into at least one of the loading holes 2, thus playing the role of the 2, 4, or 6 pole pairs.
• the block magnets should include 6 loading holes in order to perform the role of the 6 pole pair, but at least one or more loading holes is sufficient since the block magnet F2p of the present invention does not control electron beams according to a relative angle between rotatable magnetic rings as in the conventional art.
• the loading hole 2 of the assistant holder 1 guides the block magnet F2p in a radial direction and also supports the block magnet F2p at the guided position, it is preferably made of two channels of a L-type that support both sides of the block magnet F2p, and more preferably, at least one of the block magnet F2p and the channels is made of an elastic material.
• the block magnet F2p is in principle made of a composite material including an elastic rubber material and a ferrite or an Al-Ni-Co material, but in the case where the assistant holder 1 is made of a general elastic synthetic fiber, it can be made of a rigid magnetic material such as a ferrite or an Al-Ni-Co material without any problems.
• the block magnet F2p is preferably of an approximately rectangular type, and more preferably of a regular tetragon type, as shown in FIG. Ifk.
• the four sides (A through D) may be composed of a concave side whose curvature corresponds to the perimeter of each assistant holder 1.
• the block magnet F2p is composed of an elastic material such as a rubber magnet, it can be constructed to have flat sides, not concave sides, and this can make the adjusted state elastically sustained by transforming between the assistant holder 1 and the block magnet F2p in its loaded state.
• a marking 3 such as an arrow from the N pole to the S pole on at least one face of the bottom or the top of the block magnet F2p is indicated, or painting 4 is applied on at least one face.
• This marking 3 or painting 4 helps the convergence adjusting worker to figure out the direction of the magnetic poles and to adjust the block magnets in the required directions such as those shown in FIGS. 9A through 9L
• FIGS. 9A through 9L are shown methods of adjusting the convergence of electron beams using the block magnet F2p.
• FIG. 9B makes the neighboring beams shift downward and the installation of the block magnet in the outside-inside direction as shown in FIG. 9D makes shift upward.
• FIGS. 9E and 9F With respect to the outside beam on the facing side, as shown in FIGS. 9E and 9F, the beam is shifted in the opposite directions as in the cases shown in FIGS. 9B and 9D.
• FIGS. 9G and 9H correspond to FIGS. 9A and 9B.
• the present invention can also function as the 2 pole pair that moves three electron beams in the same direction by the same distance, above and below, to the right and left, as shown in FIGS. 91 through 9L.
• any function of the 2, 4, or 6 pole pairs can be performed, and when more than two block magnets are used at the same time, a variety of adjustments can be further made.
• the outside beams (R and B) become closer, thus reducing the OCV.
• the outside beams (R and B) rotate around the central beam (G).
• the convergence device of the present invention can function as a variety of pairs by combination of any side with arbitrary number of block magnets of a single construction, the magnetic force can be adjusted linearly as shown in FIG. 11.
• the convergence device can compensate for lack of convergence caused by bad elements with some arrangement of just one block magnet.
• FIGS. 12A and 12B illustrate the cases where more than one beam is shifted and where the amounts of the shifts are different. This can be seen in the following table 1.
• Table 1 In other words, if the magnetic force applied to the block magnet is strong, each beam moves in the same direction by a different amount as shown in Table 1.
• the G beam shifts linearly roughly half the distance that R beam shifts and the B beam shifts linearly roughly half the distance by which the G beam shifts.
• the magnetic flux that will adjust electron beams is formed not between magnetic poles which are separated but directly in the space adjacent to the block magnet, and the effect is therefore limited to the neighboring region, thus minimizing the interference problem. Furthermore, the adjustment is made not by rotation but by linear advancing and retracting and this makes it possible to directly anticipate the degree and the result of the adjustment, which in turn makes a precise and rapid adjustment of the convergence possible.
• the invention provides a convergence device that can obtain excellent convergence characteristics rapidly and at low cost.

Landscapes

• Video Image Reproduction Devices For Color Tv Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19636836

Family Applications (1)

Country Status (2)

Citations (4)

• 2000
  • 2000-01-06 KR KR1020000000538A patent/KR100346413B1/ko not_active IP Right Cessation
• 2001
  • 2001-01-06 WO PCT/KR2001/000024 patent/WO2001050492A1/en active Search and Examination

Patent Citations (4)

Also Published As

Similar Documents

Legal Events