KR800000610B1 - Display system utilizing beam shape correction - Google Patents

Abstract

A color picture reproducing tube utilizes three coplanar electron beams. Convergence of the three beams along at least one axis is accomplished by a deflection assembly producing a magnetic deflection field with particular astigmatism characteristics which also elliptically disorts each of the three beams in a first direction. The electron gun assembly within the picture tube includes apertured electrods which predisort the beams elliptically in a second direction orthogonal to the first direction of disortion.

Description

Display device using beam type correction

1 is a cross-sectional view showing a display device according to the present invention.

2A to 2C show a horizontal deflection magnetic field used in the FIG. 1 apparatus.

3A to 3C show a vertical deflection magnetic field used in the FIG. 1 apparatus.

4 shows a quadrupole magnetic field used in the FIG.

5 is a diagram illustrating a non-spot problem observed in an image tube not using the present invention.

6A to 6C show an electron gun component used in the first FIG. Device.

7 is a view showing a beam spot state observed in an image tube of the apparatus of FIG.

8a and 8b show a conductor distribution of a deflection yoke suitable for use in the FIG. 1 apparatus.

The present invention relates to astigmatism deflection systems for each shape pre-distortion and in-line beam convergence to compensate for deflection-induced beam distortion. The present invention relates to a color display device used.

The beam convergence of color imagers used in conventional color television receivers is driven by convergence correction waveforms with horizontal and vertical scanning ratios to converge the beams within the neck of the image and viewed on the imager's screen. A magnetic pole piece excited by an external electromagnet was used. This is commonly referred to as on-axis dynamic convergence correction. In addition, in order to correct false convergence at the edge, a calibration waveform driven by combining horizontal and vertical non-waveforms should be used. This type of structure is expensive and requires a lot of control adjustments to properly converge the beam.

In particular, a color image tube using the same cop lanar beam arranged horizontally in relation to a fluorescent stripe vertically arranged on a screen has a delta electron beam beam structure and dots arranged in three groups. A simpler dynamic convergence array can be used than the one described above using an imaging tube with fluorescent elements. It is known that quadrupole magnetic field formation windings can be used with deflection yokes to converge on the coprenaby. In general, the quadrupole winding should be caused by a number of adjustable control elements and horizontal and vertical non-waveforms used to achieve the desired non-convergence. Optionally, in addition to the quadrupole winding, the scan current through the active deflection winding can be adapted to achieve convergence, but requires a large number of adjustable control elements, making the television receiver complex and costly to manufacture and repair. This becomes expensive.

U.S. Patent No. 3,800,176, entitled "Magnetic Convergence Color Image Display," describes a device for self-converging three coprenacles of a color image tube without using a dynamic convergence device. The patent also describes the use of a simplified dynamic convergence arrangement in order to converge the beam at all points of the screen in a relatively large screen, with a diagonal screen size of approximately 25 inches. .

The magnetic convergence structure of the three in-line beams is established by creating an astigmatism deflection field, which is generally a pincushion type magnetic field created by a horizontal deflection component and a cylindrical magnetic field created by a vertical deflection component. This astigmatism is generated and controlled by the conductor distribution of the winding components placed around the neck region of the image tube. This magnetic convergence structure eliminates this, or in the case of a simplified dynamic convergence device, it is desirable to greatly reduce the dynamic convergence network and reduce set-up and maintenance time. However, in large screens such as screens with a wide deflection angle such as 110 ° and a diagonal size of approximately 63 cm, with or without a simplified dynamic convergence form with the magnetic convergence characteristics of the winding components, the electronic beam The shape is undesirably distorted by a horizontal ellipse, which is a distance function along the horizontal deflection axis from the circular point in the center area of the screen. Under this condition, the horizontal resolution of the display device is so damaged that the reproduced screen cannot be economically tolerated.

According to an embodiment of the present invention, a color display apparatus using beam type correction includes a color image tube including a copra or an electron beam gun component mounted in the image tube to make three beams for hitting the fluorescent element surface of the image tube. Include. There is also a device for converging the beam in the central region of the fluorescent surface. The deflection yoke component is installed to operate around the neck of the image tube, and the wire distribution of the yoke component is selected to create a pincushioned horizontal deflection magnetic field so that the beam of the world continues along the horizontal deflection axis, and the astigmatism is a fluorescent surface. When deflected horizontally away from the center of the beam is selected to create astigmatism for spreading each beam horizontally as each beam reaches the fluorescent surface. The electron gun component includes holes in at least one electrode that is vertically elliptical to form an elliptical beam perpendicular to the center of the fluorescent surface to reduce the horizontal distortion of the beam caused by the deflection yoke component.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional top view of a display device according to the present invention. The color image tube 20 includes a glass shell 70 and a face plate 21. On the inner surface of the face plate 21 there are a series of repeating groups of blue, green and red fluorescent components 22a, 22b and 22c. In the neck region of the image tube 20, an electron gun component 25 for making three coplanar beams B, G and R passing through the holes 24 of the hole mask 23 so as to collide with the respective color fluorescent elements. have. Around the neck area of the image tube 20 is a deflection yoke including a ferrite core 26 having conductors 27 forming vertical and horizontal deflection coils. The deflection yoke itself contains a quadrupole magnetic field forming conductor, which will be explained below. Behind the deflection yoke around the neck of the video tube is a positive convergence component 28. This part is a suitable form of adjustable quadrupole and hexapole magnetic field for arranging two external electron beams in relation to the central electron beam. Behind the constant convergence component 28 is a color purity adjusting device 29. The device consists of two rotatable metal rings, each of which is magnetized in opposite polarity. This color purity ring component 29 acts to move all three in-line beams together. The positive convergence part 28 and the color purity part 29 may be separated parts as shown here, or may be combined into one device.

FIG. 2a shows a deflection magnetic field made by the deflection yoke component of FIG. 1, which is required to horizontally deflect the electron beam and at the same time to have the magnetic convergence of the beam along the horizontal deflection axis without requiring additional dynamic convergence correction devices. It is shown. The magnetic flux lines 30 form a pincushion-type deflection magnetic field that increases strength in the horizontal direction away from the magnetic field center. The net horizontal deflection field shown in FIG. 2A generally includes ancillary component magnetic fields shown in FIGS. 2B and 2C. 2b shows a uniform deflection magnetic field, such as an integral magnetic field formed by a horizontal deflection coil exhibiting isotropic astigmatism. The deflection force is perpendicular to the vertically arranged uniform line of the magnetic flux 33. This homogeneous magnetic field, acting on three electron beams converged at the center of the fluorescent surface by conventional positive convergence components, is deflected far from the center of the plane in the horizontal direction due to the image magnetic field curvature, causing the beam to be overconverged. To be. A nonclinical force is applied to converge the beam along the horizontal axis to compensate for overconvergence caused by the effects of image magnetic field curvature. As mentioned in the patent, this is done by creating a net horizontal deflection field astigmatism. In particular, this magnetic field has the negative horizontal isotropic astigmatism characteristic shown in FIG. 2A. This astigmatism field can be made in several ways.

As shown in FIG. 2C, the axial magnetic field can be generated by the third harmonic energy of the activated horizontal deflection coil by appropriately arranging the coil leads in the deflection yoke. Examples of suitable lead distributions are shown in FIGS. 8A and 8B. The magnetic flux line 31 of FIG. 2C is generally concentrated along the line 32 and combines with the uniform magnetic field of FIG. 2B to calculate the magnetic convergence magnetic field of FIG. 2A and the required astigmatism deflection. Instead of a pole magnetic field, a quadrupole winding, which is a wound component wound around the deflection yoke along the deflection coil or mounted around the image tube adjacent to the deflection yoke, can be used to create non-uniform magnetic fields to achieve magnetic convergence. have. The four polarities of this winding are approximately 45 degrees away from the horizontal and vertical deflection axes. A suitable magnetic field is created when this winding is excited by the horizontal specific current. For example, quadrupole windings generally require parabolic currents, and six pole windings require sawtooth currents, which are normal scan currents.

Of course, these three beams must be converged at every point on the raster and not along the horizontal axis. According to the discussion with respect to FIGS. 2A-2C, even when the beam is concentrated along the horizontal axis, the beam is overconverged at the ends of the raster corners and the vertical deflection axis, resulting in traps. A trap is a state where the horizontal line separates not along the two deflection axes. In order to correct these conditions, the astigmatism characteristic of the vertical deflection field must also be controlled.

3A to 3C show the characteristics of the vertical deflection field. FIG. 3A shows a net deflecting magnetic field having a cylindrical shape and exhibiting positive polarity isotropic astigmatism characteristics. The magnetic flux lines 34 become more complex toward the center of the magnetic field, and the strength of the magnetic field decreases in the vertical direction away from the center. This magnetic field forces three non-clinical forces to correct for the horizontal hyperconvergence of the beam in the upper and lower parts and corners of the fluorescent surface. The magnetic field of FIG. 3A is comprised of the superimposed magnetic field of FIG. 3B and FIG. 3C.

3b shows a uniform vertical deflection magnetic field including a flux line 35 extending in the horizontal direction. This astigmatism field also deflects the beam, but does not correct the trap beam state that is overconverged horizontally in the upper and lower portions of the scanned raster. FIG. 3C shows a polar magnetic field including a magnetic flux line 36 which concentrates the magnetic field in the direction of the arrow on the line 37. Since this magnetic field is not uniform, it forms a desirable convergence with the deflection magnetic field of FIG. 3a when added to the uniform magnetic field of FIG. 3b. The polar magnetic field of FIG. 3C is generated by the energy harmonics in the vertical deflection coil when excited, and can be produced by appropriately disposing the vertical deflection coil conductor around the ferrite core of the deflection yoke as shown in FIGS. 8A and 8B. have.

As in the description of the horizontal deflection field, the cylindrical vertical magnetic field can be made by adding non-uniformity by a device that does not control the deflection coil winding distribution. For example, a vertical coil is wound to create an astigmatism magnetic field as shown in FIG. 3B, and a quadrupole winding in a separation winding located on or near the deflection yoke is used. This quadrupole winding has poles located approximately 45 degrees between the horizontal and vertical deflection axes as shown in FIG.

The patent mentioned above describes a complete magnetic convergence device. This does not require dynamic convergence. That is, a deflection coil winding conventionally excited is provided to provide a specific astigmatism magnetic field required for convergence. On a device with a smaller picture tube, the convergence is parallel at all points on the screen, with the beams converged slightly downward at the end of the horizontal deflection and slightly upward at the end of the vertical deflection axis. Is done. This saves cost and complexity by eliminating all dynamic convergence devices and their ancillary installations, making it possible to economically accept images played on screen. However, in a large screen size such as an image tube having a screen diagonal size of 63 mm, the distance between the deflection plate C of FIG. 1 and the screen is increased, and the convergence error is enlarged and cannot be tolerated. The magnetic convergence structure is supplemented by a simplified dynamic convergence array using dynamic convergence along only one deflection axis. In such an arrangement, the horizontal deflection coils can be designed to achieve magnetic convergence along the horizontal deflection axis. This vertical coil can be designed to create zero traps in the corners. This leaves an overconverged vertical line along the top and bottom of the raster. These errors must be resolved appropriately so that the simplified overconvergence is corrected. The quadrupole winding, as shown in Figure 4, which makes the quadrupole ridge corrects these hyperconvergence errors. The magnetic flux line 38 in FIG. 4 generally concentrates the magnetic field in the direction of the arrow of the line 39. This quadrupole magnetic field acts to horizontally converge the vertical line so that all rasters converge. It eliminates the need for horizontal frequency or corner dynamic convergence current, reducing cost without compromising performance. This raises the need for conventional dynamic convergence electromagnets and their drive current circuits. Also, an apparatus for generating a quadrupole magnetic field for simplified dynamic convergence is not suitable for the present invention. This magnetic field can be generated by an added conductor wound on the deflection yoke as shown in Figs. 8A and 8B. This quadrupole magnetic field can be generated by the unbalance of the windings arranged around the image tube adjacent to the yoke and the current through the vertical deflection coil.

In addition to the design of a deflection coil to create a non-convergence deflection magnetic field, the above-mentioned patent further discloses that the deflection field center is the center of the world's in-line electron beam to balance the convergence state around the edge of the screen. It is described that they can be arranged together. This can be done by designing the deflection yoke such that the smallest inner diameter is 1 to 3 mm larger than the outer diameter of the neck portion of the image tube. At this time, the yoke is moved at right angles to the central beam axis so that the central length axis of the deflection magnetic field coincides with the central beam axis. The yoke can also be skewed to achieve an optimal convergence arrangement as needed. This yoke is then fixed in position arranged by a suitable yoke mounting arrangement. To selectively position the yoke mechanically, the horizontal and vertical scan current through half of each coil is electrically slightly centered in the center of the electron beam deflection field so that it is aligned with the center beam for optimal convergence. It can be unbalanced to move. This can be done by adding a series impedance to one half of the coil or by shunting some scan current around one half of the coil.

What has been described above relates to a number of variations of a coprene or display device that does not use an inner pole portion to act as a flux indicator for converging the magnetic field. However, all of these devices used only the above-described magnetic convergence structure. The magnetic convergence structure with simplified dynamic convergence or astigmatism deflection coils combines the quadrupole windings excited with vertical and horizontal scanning ratios and the core used in conventional delta guns to create the required astigmatism convergence field. Similar. Since this self-convergence or simplified convergence array is used as part of the present invention, it can be seen that the arrangement shows the form of the magnetic convergence array used as part of the present invention.

The above-mentioned self-convergence simplified convergence apparatus has undesirable characteristics, but first, the individual electron beams are out of focus by the astigmatism deflection magnetic field. This does not cause a significant problem in a small picture shop, but degrades the picture quality in a big picture shop. In particular, each beam is vertically suppressed and stretched horizontally as it is deflected in the horizontal direction, such that the beam spot forms an ellipse. This ellipse becomes more firm as a function of the beams in the horizontal direction away from the center of the screen. This case can be clearly seen by referring to FIG. 5, which shows a beam spot state at various points in the upper right quadrant of the screen 40. FIG.

In FIG. 5, the beam spot 41 at the center of the screen is circular. The circular beam is generated by an electron gun and focused on the screen. This dimension indicates the amount of ellipse or distortion of the beam spot at various locations. Beam spots vary in size with the amount of current in the beam. The beam current changes as a function of the video signal coupled to the electron beam gun component. In large-angle video screens, the beam spot changes from a circle of approximately 2 mm to a circle of approximately 4.5 mm at the center of the screen. The beam spot size changes appropriately at different points on the screen. At the end of the horizontal or X deflection axis, the beamspot 43 forms an ellipse with a major axis dimension of 7.5 proportional to the central dimension of 4.5. In the corner, the spot 44 has a main ellipse axis dimension of 8.5. At the top of the vertical or Y deflection axis, the beam spot 42 does not vary significantly from the center spot size. Clearly, spots 43 and 44 show a decrease in beam spots that will adversely affect horizontal resolution. The arrangement according to the invention uses a highly preferred magnetic convergence deflection device without undesirably decentralizing each electron beam.

6A-6C illustrate electron gun components suitable for use in the device of the present invention. In general, the electron gun component is vertically elliptical and provides three in-line electron beams using the above described magnetic convergence or simplified convergence device, greatly reducing the deflection density of the beam.

In FIG. 6a, the gun 25 comprises two glass support rods 50 with several grid electrodes installed. These electrodes are spaced at equal intervals in three coplanar cathodes 51 (for each beam), control grid electrode 52, shielded grid electrode 53, first acceleration and convergence electrode 54, The second acceleration and convergence electrode 55 and the shielding cup 56 are included. All of these elements are spaced along the glass stem 50.

Each cathode 51 includes a cathode sleeve 57 approaching the forward end by a cap 58 comprising an end coating 59 of electrospinning material. Each sleeve is supported on a cathode support tube 60. The tube 60 is supported on the rod 50 by four straps 61 and 62. Each cathode 51 has a leg 64 welded to a heater strap 65 mounted to the rod 50 by a stud 67 on the rod 50 and within the sleeve 57. It is indirectly heated by the heater coil 63.

The control and shielding grid electrodes 52 and 53 are closely spaced (approximately 0.23 mm) flat plates, each of which is centered with a cathode coating 50 and extends toward the screen 21 with two externals. It has three holes 68R, 68G and 68B, 69R, 69G and 69B arranged along the non-passage path 70R and 70B and the center beam passage 70G, respectively. . The outer beam passages 70R and 70B are spaced apart from the center beam passage 70G at equal intervals. Preferably, the initial portions of the beam passages 70R, 70B, and 70G are parallel and are approximately 5 mm apart.

The first acceleration and convergence electrodes 54 include first and second cup-shaped members 71 and 72 connected to their open ends, respectively. The first cup-shaped member 71 is adjacent to the grid electrode 53 and has three holes 74R of medium size of approximately 1.5 mm arranged on the non-passage paths 70R, 70B, and 70G, respectively. , 74G, and 74B. The second cup-shaped member 72 has three large (approximately 4 mm) holes 75R, 75G and 75B arranged in three non-pass passages.

The second acceleration and convergence electrode 55 is also cup-shaped, the base plate portion 76 adjacent to the first acceleration electrode 54 (approximately 1.5 mm) and the sidewall or flange extending toward the screen ( Flange) 77. The base portion 76 is formed of holes 78R, 78G, and 78B in the world that are slightly larger (approximately 4.4 mm) than the adjacent holes 75R, 75G, and 75B of the electrode 54. do. The middle hole 78G is arranged in the adjacent middle hole 75G (and a middle non-pass passage 70G), and is symmetrical between the holes 75G and 78G when the electrodes 54 and 55 are excited at different voltages. It provides a non-imconvergent field. The two outer holes 78R and 78G are offset slightly outward with respect to the corresponding outer holes 75R and 75B, so as to be asymmetrical between each pair of outer holes when the electrodes 54 and 55 are excited. By providing an electromagnetic field, each of the external beams 70R and 70B converges near the plane, and each of the external beams toward the intermediate beam 70G, together with the intermediate beam near the plane, Deflect. In the illustrated example, the offset of the beam holes 78R and 78B may be about 0.15 mm.

In order to correct the beams mentioned above, which are flattened as the horizontal deflection angle increases, each beam is defocused vertically at the center of the plane so that it is distorted in the gun so that unbiased beam spots extend vertically. Precursion and preforming of the beam are achieved by using vertically extending elliptical holes in the electron gun component. In the total part shown, the two grids closest to the cathode, i.e. the shielding grid electrode 53 of the control grid electrode 52, comprise an elliptical hole vertically, although any other suitable beamforming arrangement is used. The elliptical properties of the holes 68R, 68G and 68B in the control grid 52 are shown in FIG. 6B, and the elliptical properties of the holes 69R, 69G and 69B in the shielding grid 54 are shown in FIG. It is shown in Figure 6c. Of course, the degree of ellipse required depends on the particular type of imager used. However, the 63 cm described above having a soft electron beam spot ellipse of 2.9 / 1.0 when not using the present invention. For a central beam of V 110 °, a vertical elliptical hole with an ellipse of 1.6 / 1.0 provides beam electroforming to obtain a circular beam at the edge of the face. Typical hole dimensions for this elliptic need are approximately 0.5 mm horizontally and 0.8 mm vertically.

FIG. 7 shows the effect of beamspot observation on screen of a combination of the present invention comprising an electron gun component and a self-convergence or simplified convergence deflector that makes a beam formed in a vertical ellipse. The beam beam in FIG. 7 is shown in the upper right quadrant 40 of the fluorescent surface similarly to FIG. At the center of the screen or at the intersections of the horizontal and vertical or X and Y deflection axes, the beam spot 41 'is a vertically formed ellipse having the indicated proportional dimension. This vertical ellipse remains, but slightly increased in size at the end of the vertical deflection axis, as shown by beam spot 42 '. A significant improvement is observed at the ends and corners of the horizontal axis by comparing each beam spot 43 'and 44' with the corresponding spots 43 and 44 in FIG. The major dimension of the horizontal, elliptical beam spot is substantially reduced. This increases the resolution of the device so that a satisfactory playback screen appears to the viewer. The nonclinical effect is almost the same as in the remaining three quadrants of the screen.

Elliptical holes of the control electrode 52 and the shielding electrode 53 in FIGS. 6A to 6C form three in-line beams in a vertical ellipse. At this time, these elliptical beams are substantially converged by circular convergence and acceleration electrodes 54 and 55. The vertically arranged chief rays of each beam crossover farther from the cathode to the horizon than the horizontally arranged chief rays that cross over in the vertical lines due to the action of the convergent magnetic field of the elliptical beam. In order to obtain the minimum horizontal dimension of the beam spot on the fluorescent film, the intensity of the main convergence lens (the convergence potential applied to the electrodes 54 and 55) is adjusted to illuminate the image of the vertical crossover on the fluorescent surface.

FIG. 8A shows the conductor winding distribution of a quadrant of a toroidal deflection yoke suitable for use as part of the invention, such as applied to a display device using an image tube having a deflection angle of 110 degrees and a screen diagonal dimension of 63 cm. . The baselines X and Y represent the vertical and horizontal deflection axes of the toroidal deflection yoke, the deflection yoke of FIG. As shown in FIG. 8A, the conductors shown in a circle form a horizontal magnetic field forming deflection coil.

The conductor marked with X represents a perpendicular magnetic field formation deflection coil. The triangular conductor is a conductor that forms a separate quadrupole magnetic field forming coil winding portion wound annularly around the core of the toroidal yoke. 8A there are four conductor layers spaced and positioned as shown to form the preferred coil winding portion in this embodiment.

8B shows the arrangement of the conductor distribution W of the deflection yoke used in connection with the present invention. In each of the quadrants I-IV, part W is identical to that shown in Figure 8a. Each cross section surrounds the core from the X axis to the Y axis in each quadrant. These conductors are wound annularly around the ferrite core 26. The return conductors appearing on the outer periphery of the core 26 are not shown in FIG. 8B.

Claims (1)

A color image tube, a color fluorescent surface, a multi-hole color selection electrode away from the screen, a coplanar or electron beam total component for generating three electron beams on the surface through the electrodes, and the beam convergence in the central region of the fluorescent surface. And a deflection yoke component comprising horizontal and vertical deflection coils, in particular the lead distribution of the coils to be converged along the horizontal axis of the three beams and landing patterns of the respective beams. The total part selected to form a pincushioned horizontal deflection magnetic field that is distorted in the horizontal direction, the total part including the holes of at least one grid electrode, has the center of the fluorescent surface to reduce the horizontal distortion of the beam caused by the deflecting part. Vertically to form an elliptical landing pattern of the beam at Display apparatus using a non-corrected imhyeong characterized in that the oval.

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