KR20010099625A - Color display device having quadrupole convergence coils - Google Patents

Abstract

The invention is an inline electron gun 5 which produces three electron beams 6, 7 and 8, and a convergence unit which dynamically affects the convergence of the electron beam and preferably reduces the distance p between the electron beams. A color display device comprising 14 '. The convergence unit 14 'comprises a ring shaped element 21' with a coil 22 '. The coil 22 'is N ( ) = N ₀ cos (2 Winding density distribution given by) + C {N ( ), It was wound in a donut-shaped winding direction. here Is the angle enclosed by the X direction and the line segment centering the coil element, the range of which is between 0 ° and 360 °, N ₀ is Winding density when is 0 °, N ( ) Represents the winding direction, and C is a constant of 0, + N ₀ or -N ₀ .

Description

COLOR DISPLAY DEVICE HAVING QUADRUPOLE CONVERGENCE COILS with 4-pole convergence coil

Such display devices are known.

The purpose is to make the exterior of the display window flatter so that the image reproduced on the color display device is perceived by the viewer as flat. However, increasing the radius of curvature of the outer surface will cause an increase in many problems. The radius of curvature of the color selection electrode and the inner surface of the display window should increase, and as the color selection electrode becomes flat, the strength of the color selection electrode decreases, thus increasing the sensitivity to doming and vibration. . An alternative solution to this problem is to bend the inside of the display window larger than the outside. Because of this, a color selection electrode having a relatively small radius of curvature can be used. Because of this, the domming and vibration problems are reduced, but other problems occur instead. The display window is much thicker on the outside than the center. As a result, the weight of the display window increases, and the intensity of the image decreases substantially as it goes to the edge.

European patent EP 0,421,523 describes a color cathode ray tube with an in-brow gun, a pincushion correcting yoke and an eyebrow effect electron-optical distortion correction device comprising two pairs of coils. Each pair has a coil in the beam plane, on each outer electron beam side of the neck. Coil pairs are sawtooth waves with a bow-tie envelop, spaced along the Z axis between the electron gun and the yoke and synchronized with the raster scan to correct dynamic and asymmetric eyebrow effects, which are manifested as purity defects on the raster. Driven by current.

WO 99/34392 discloses a deflection for deflecting a color cathode ray tube equipped with an inline electron gun which produces three electron beams substantially positioned on an unfolded plane in the X direction of a rectangular XZ coordinate system, a color selection electrode, and an electron beam located on the deflection plane Means and first and second influencing means for dynamically influencing the convergence of the electron beam and for reducing the distance between the electron beams at the deflection plane position. WO 99/34392 describes many different ways in which the means of induction can be embodied. One of the possible methods mentioned is to combine the second inducing means and the deflection means. The second inducing means can be embodied in four coils that produce a four-pole magnetic field.

The present 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 beam across the color selection electrode.

1 is a cross-sectional view of a display device, in which the invention is schematically illustrated.

2a and 2b show an embodiment of a second inducing means according to the invention;

3a and 3b show a first part and a second part of a ring shaped element according to an embodiment of the invention;

4 shows a deflection means according to an embodiment of the invention.

5 illustrates another embodiment of the present invention.

The drawings are not drawn to scale. In the drawings, like reference numerals refer to like parts throughout.

It is an object of the present invention to provide an improved color display device. For this purpose, the present 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.

These and other objects of the present invention will become apparent and clear with reference to the embodiments described below.

The display device shown in FIG. 1 comprises a cathode ray tube having a display window 2, a conical portion 3 and an evacuated envelope 1 comprising a neck 4, in this example a color display. Cathode ray tube. The neck 4 has an inline electron gun 5 which produces three electron beams 6, 7 and 8 directed in the X-direction of the vertical coordinate system, ie in the in-line plane. In the unbiased state, the central electron beam 7 substantially coincides with the central axis 9 of the cathode ray tube, which is directed in the Z direction. The third direction, the Y direction, is directed in a direction perpendicular to the inline plane (not shown in the figure). In general, during operating operating conditions, the cathode ray tube is positioned in such a way that the X-Z plane coincides with the horizontal plane and the Y direction coincides with the vertical direction.

The display screen 10 is provided on an inner surface of the display window. Display screen 10 includes a number of phosphorescent elements that emit red, green, and blue luminescing. On the way to the display screen, the electron beam is deflected across the display screen by an electromagnetic deflection unit 51 and placed in front of the display window 2 and placed on a thin plate with apertures 12. It passes through the color selection electrode 11 it contains. Since the three electron beams 6, 7 and 8 pass through the aperture 12 of the color selection electrode at a small angle with respect to each other, each electron beam affects only one color phosphor element. The deflection unit 51 includes, in addition to the coil holder 13, a deflection coil 13 'for deflecting the electron beam in two directions perpendicular to each other. A ring shaped element, a so-called yoke ring, is located around the deflection coil 13 '. The reason for using the yoke ring (usually containing ferrite) is to "short-circuit" the magnetic flux outside the coil. Without the yoke ring, an excessively large current passing through the deflection coil It will be common and will also cause disturbing (magnetic) stray fields .. The display device also includes means for generating a voltage for supplying the electron gun component through feedthroughs during operation. The surface 20 is schematically shown, and the distance p between the electron beams 6 and 8 is also shown on this surface, and the distance q between the color selection electrode and the display screen is also shown. Inversely proportional to distance p.

The color display device comprises two beam convergence inducing units 14, 14 ′, the first unit 14 serving as a deflection function for one direction during operation, such that the outermost electron beams are dynamically bent towards each other. The second unit 14 ′ dynamically deflects the outermost electron beam in the opposite direction.

The two units 14, 14 ′ are located at a constant distance from each other and are used as a deflection function to change the distance p as a deflection function in such a way that the distance p decreases in at least one direction. The first unit 14 is located close to the electron gun and is called "gun quadrupole", and the second unit 14 'is located close to the deflection unit and is called "yoke quadrupole".

It is easy to integrate the unit 14 'and the deflection unit 51 by winding a coil 22' which generates a dynamic 4-pole electromagnetic field in the ring-shaped element 21 '.

The means 14 '("quadrupole yoke ring") are obtained by making a coil 22' from an electrical conductor, which is N ( ) = N ₀ cos (2 Winding density distribution by) + C {N ( )} In a donut-shaped (toroidally) winding direction. here, Is an angle surrounded by the X direction and the line connecting the coil element to the center, the range of which is between 0 ° and 360 °, N ₀ is Winding density when is 0 °, N ( ) Indicates the winding direction, and C is a constant.

An advantage of this embodiment is that an almost pure quadrupole magnetic field is generated, i.e., the presence of another multipolar magnetic field is greatly suppressed.

Since the line size is finite, only an approximation of the winding density can actually be used.

That is, an embodiment using the approximation value when the constant C takes a value of 0 is shown in Figs. 2A and 2B. This embodiment is the winding density,

N ( ) = N ₀ cos (2 )

And a package 30 of electrical conductor, which is toroidally wound around the yoke ring 21 '.

In this particular embodiment, the electrical conductors are wound in the grooves 34 of the yoke ring 21 ', 15 degrees apart from each other. Winding method is as follows.

= 18 turns in a groove at 0 ° (a position),

= 15 turns in groove with 15 ° (b position),

= 9 turns at 30 ° (c position),

= 45 ° (d position) without detection

In a groove with = 60 ° (e position), wind nine times in the opposite direction,

= 15 turns at 75 ° (f position),

= 90 ° (g position), 18 turns. This ideal winding density {N ( The approximation of)} proved to be actually good.

Reference is made to FIG. 2B for another embodiment where the constant C takes on N ₀ or -N ₀ . This winding density approximation is obtained by

= 0 wounds in grooves at 0 ° (a position),

= 3 turns in a groove at 15 ° (b position),

= 9 turns at 30 ° (c position),

= 18 turns at 45 ° (d position),

In a groove with = 60 ° (e position), wind 27 times in the opposite direction,

= 33 turns at 75 ° (f position),

= 90 degrees (g position), 36 turns.

This ideal winding density {N ( The approximation of)} has the advantage that it is not necessary to wind the coil in the a position (i.e., the eastern position of the yoke ring) (the same applies in the western position). Thus, the coil has only two packages of wound wire, not four packages. In the east and west positions, the yoke ring can be separated by a wound coil and / or yoke ring assembly. In this way, double saddle yokes may also be used in which the coil ends located on the electron gun side have a diameter larger than the inner diameter of the yoke ring. Due to this saddle-shaped yoke, it is necessary to be able to detach the yoke ring while assembling the yoke. In addition, significant line frequent voltage generation can be avoided by winding the two packages separately on the layers. This is effective because the line flux changes sign at the top and bottom of the yoke ring. In addition, since the distribution of the line wound on the upper part of the quadrupole has the same winding sign, no change in the winding direction occurs when this upper part is wound, and consequently the winding process is improved.

3A and 3B show an embodiment of the present invention. 3 a shows a first part 60 of the ring-shaped element 21 ′ which is closest to the electron gun 5. This part 60 has four coils 22 'that produce a four-pole magnetic field. cos (2 ), Coils wound in a toroidal-way according to a wound distribution with C = 0 are shown. In order to facilitate the winding process and to retain the individual wire elements of the coil 22 'in the right position of the first part 60, the first part is provided with a groove in which the wound coil is located. Having rings 64, 66. 3b shows a second portion 68 of the ring shaped element 21 ′, which is closest to the display window 2. When applied to a cathode ray tube, these two parts 60, 68 can be connected to one another by any existing connection means, ie adhesives or tapes. The connection between these two parts is not essential for proper performance.

This embodiment of the present invention has the advantage that the means 14 'can reduce the impact on certain imaging defects. Experiments have shown that during operation of the cathode ray tube with means 14 ′, certain image defects such as over-correction for nonlinearity and east / west pincushion raster distortion in electron beam deflection may occur. It was noted. The inventors have found that this influence can be reduced by dividing the ring shaped element 21 'into two parts 60, 68. The first part 60 is located closer to the inline electron gun 5 than the second part 68, and the first part 60 and / or the second part 68 has four coils 22 ′. do. Preferably, it is wound around a core portion closest to the electron gun. The measurement offers the opportunity to move the two core parts independently of each other, thus improving the raster and convergence performance of the cathode ray tube.

4 shows two parts 60, 68 according to the invention when the two parts 60, 68 are positioned around the deflection coil 13 ′ and the coil holder 13. The first portion 60 has four coils 22 'and rings 64, 66 that generate a four-pole magnetic field.

Figure 5 shows another embodiment according to the present invention. The 4-pole magnetic field can be simply generated by the magnetic field coil set 70 itself without any additional coils. This is realized by adding an additional signal to the set of magnetic field coils in addition to the normal magnetic field signal for electromagnetic deflection. This additional signal is then used to generate a four pole magnetic field through the set of magnetic field coils. For example, assume that 2 A (amps) of input signals 72, 74 are supplied to a magnetic field coil set 70 comprising two coils. For example, a signal for a 4-pole magnetic field 76 with a value of 1 A is added to the input signals 72, 74 via asymmetric drive means 80, so that two asymmetric signals with values of 1 A and 3 A, respectively. Divided by. These asymmetrical signals are supplied to two coils in the magnetic field coil set 70, making them magnetic fields for deflection of the electron and four pole magnetic fields. This asymmetric drive means 80 may be in the form of any existing means within the reach of those skilled in the art. For example, it may be a set of two diodes properly positioned between the coil and the input signals 72, 74.

A preferred method of manufacturing the second convergence unit 14 '("yoke ring quadrupole"), in which the coil 22' comprises layers, provides the following steps: ring shaped element 21 '. And winding an electrical conductor in the form of a donut around the ring-shaped element 21 '. The winding step consists of a first step of winding the first layer of each coil and at least one additional step of winding another layer of each coil.

This method of winding the second convergence unit differs from the simple method of winding the coils in one layer. However, this simple method can cause ringing problems and reliability problems. Ringing is an unwanted inductive interference phenomenon between the deflection unit 51 frame coil 13 'and the lines. The preferred winding method according to the invention can be seen as having many interconnections between the four coils 22.

In summary, the preferred embodiment of the present invention provides an inline electron gun 5 which produces three electron beams 6, 7 and 8, and a dynamic effect on the convergence of the electron beams and reducing the distance p between the electron beams. To a color display device comprising a convergence unit 14 '. The convergence unit 14 'includes a ring shaped element 21' with four coils 22 '. The coil 22 'becomes an electrical conductor, and N ( ) = N ₀ cos (2 Winding density distribution by) + C {N ( According to the donut-shaped winding. here, Is the angle enclosed by the X direction and the line connecting the coil element to the center, the range of which is between 0 ° and 360 °, N ₀ is Winding density when is 0 °, N ( ) Indicates the winding direction, and C is a constant.

It should be noted that the foregoing embodiments are intended to illustrate, not limit the invention, and those skilled in the art can design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprises" does not exclude the presence of elements or steps other than those stated in a claim. Singular words used in this specification do not exclude the presence of a plurality of such elements. The simple fact that certain measurements are cited in different independent claims does not indicate that a combination of these measurements cannot be used to advantage. In a device claim enumerating a plurality of means, some of these means may be incorporated by the same hardware item.

Claims (11)

An inline electron gun 5 for generating three electron beams 6, 7 and 8 substantially positioned on the plane extending in the X direction of the rectangular X-Z coordinate system, Deflection means 51 for deflecting the electron beams 6, 7 and 8, A convergence means 14 ′ that dynamically affects the convergence of the electron beam, the convergence means 14 ′ comprising means for generating a magnetic field consistent with a quadrupole magnetic field generated by the coil 22 ′, The coil 22 'is composed of an electrical conductor, ) = N ₀ cos (2 Winding density distribution given by) + C {N ( )}, In the form of a donut, in the winding direction, where Is the angle enclosed by the X direction and the line connecting the coil element to the center, the angle ranges between 0 ° and 360 °, N ₀ is Winding density when is 0 °, N ( Denotes a winding direction, and C is a constant. 2. The color display device according to claim 1, wherein the means for generating a four-pole magnetic field comprises a ring shaped element (21 ') having the coil (22'). 3. The coil (22 ') of the convergence means (14') comprises a package (30) of electrical conductor wires, wherein the package (30) is N (3). ) = N ₀ cos (2 Winding density distribution given by) + C {N ( )} Is wound in the winding direction, in the form of a donut, where Is an angle surrounded by a line connecting the center of the package element with the X direction. The color display device of claim 1, wherein the constant C is zero. The color display device of claim 1, wherein the constant C is + N ₀ or -N ₀ . 3. The ring-shaped element 21 'according to claim 2 comprises two parts 60 and 68, the first part 60 being located closer to the inline electron gun 5 than the second part 68. Wherein the first portion (60) and / or the second portion (68) comprises a coil (22 '). 2. The deflection means (51) according to claim 1, wherein the deflection means (51) comprises a magnetic field coil set, and wherein the means for generating a four-pole magnetic field comprises the magnetic field coil set and means for driving the magnetic field coil set asymmetrically, Color display device. Deflection comprising a deflection coil 13 ′ and convergence means 14 ′ for dynamically influencing the convergence of the electron beams 6, 7 and 8 and reducing the distance p between the electron beams at the deflection plane position. As the unit 51, The convergence means 14 'comprises a ring-shaped element 21' with a coil 22 ', the coil 22' consisting of electrical conductors, ) = N ₀ cos (2 Winding density distribution given by) + C {N ( )}, In the form of a donut, in the winding direction, where Is the angle enclosed by the X direction and the line connecting the coil element to the center, the angle ranges between 0 ° and 360 °, N ₀ is Winding density when is 0 °, N ( Indicates a winding direction, and C is a constant. 9. The ring-shaped element 21 'comprises two parts 60 and 68, the first part 60 being located closer to the inline electron gun 5 than the second part 68, Deflection unit, wherein the first portion (60) and / or the second portion (68) comprises the coil (22 '). A method of manufacturing a convergence unit 14 'consisting of a ring-shaped element 21' with a coil 22 ', which dynamically affects the convergence of an electron beam in the color display device 1, Providing the ring shaped element 21 ', N ( ) = N ₀ cos (2 Winding density distribution given by) + C {N ( ), Winding an electrical conductor in a winding direction, in the form of a donut, around the ring-shaped element, wherein Is the angle enclosed by the X direction and the line segment centering the coil element, the range of which is between 0 ° and 360 °, N ₀ is Winding density when is 0 °, N ( Denotes a winding direction, and C is a constant winding method of the electric conducting unit. 11. A coil according to claim 10, wherein each coil (22 ') has layers, the winding step being a first step of winding a first layer of each of the coils (22) and each of the coils (22'). And at least one other step of winding another layer of the convergence unit.