EP1139378A1 - Deflection unit for in-line electron beam tubes - Google Patents

Abstract

The run of a groove at one point is altered to allow coil wires (40) held in the groove to run in a bent direction near where it is altered. In a preferred form grooves (10,30) are separated from each other by groove walls with dents if necessary and a thickening layer (50) near where the groove run is altered.

Description

The invention relates generally to deflection units for in-line electron beam tubes and particularly relates to those deflection units that a Coil body with essentially straight grooves for receiving wound Include coil wires.

In in-line type color picture tubes, the electron gun is for generation three coplanar electron beams that converge on the screen. The deflection unit arranged around the neck portion of the picture tube is used to direct the electron beams in one direction or another from their deflect normally straight path so that the rays are on selected Impact points on the screen to generate a visual signal. By suitable variation of the magnetic deflection fields over time, the electron beams can up or down and right or left across the screen to get distracted.

In-line color picture tubes have three electron guns next to each other. To the deflecting generated electron beams in the X and Y directions, generates the on Color tube mounted, funnel-shaped deflection deflection fields, so on the screen a self-converging image is created without north-south raster distortion. This funnel-shaped deflection unit essentially consists of a pair of horizontal coils, which creates a magnetic field that deflects the rays in the X direction, one Vertical coil pair for deflection in the Y direction, a ferrite core that holds the coils encloses, and correction magnets and possibly soft magnetic field formers.

The bobbins for the horizontal and vertical coil pairs are usually in Grooving technology built up. A section of such a coil former is shown in FIG. 1a shown. As can be seen from the figure, the coil body has a variety of straight grooves 10, 20, 30 into which a winding wire 40 when winding the Coil is inserted. As a result of the straight groove, the winding wire is also just wrapped. The field distribution can be influenced by changing the distance or an optionally existing angle between adjacent grooves possible. Figure 1b shows one of the grooves used in cross section.

Figures 2a and 2b show the field profiles of the horizontal and vertical deflection field along the Z direction, i.e. towards the screen too. Like that Figures can be seen, the field distribution within the deflection unit changeable. In particular, the field courses in the front and rear area give way the deflection unit from each other. Under the term "front area" here Understand the area of the deflection unit, which faces the screen.

The following two types of errors can occur in in-line electron beam tubes, among others occur: convergence errors and geometry errors.

Convergence errors occur when the different color separation images are not congruent are. A special form of convergence errors occurs with in-line electron beam tubes as a coma error because the grid dimensions of the three electron beams are different on the screen. This is a result of the eccentric Position of the outer electron beams in relation to the horizontal and vertical deflection fields.

Geometry errors cause a deviation in the grid geometry on the screen that of an ideal grid regardless of any convergence errors. The cause for geometry errors are the different path lengths of the electrons to the individual points on the screen.

Corrective mechanisms based on the correction are therefore known in the prior art of convergence and geometry errors. In particular, this will also thereby achieved that by complex winding technology at certain Z positions Deflection unit inhomogeneous deflection fields are generated, as shown in Figures 3a to 3d are made clear. These figures show a horizontal barrel field in FIG. 3a, in FIG 3b is a horizontal pillow field, in FIG. 3c a vertical barrel field and in FIG. 3d vertical pillow field.

The use of such pillow-shaped or barrel-shaped magnetic deflection fields however, only allows a convergence error or geometry error correction up to a certain level of accuracy.

The invention is therefore based on the object of specifying a possibility with which it manages to mount deflection units on an in-line electron tube with smaller ones To produce convergence and geometry errors.

This object is achieved according to the invention by a deflection unit for mounting on an in-line electron beam tube solved the a bobbin with grooves for receiving wound coil wires, the grooves being substantially straight. The groove wall of at least one groove at at least one point is changed in such a way that the coil wires received in the slot in the area of the changed slot wall assume a curved course.

This selective change in the groove wall results in a finely adjustable, targeted error correction enables, which also allows field courses that of the in Figures 3a to 3d shown field courses deviate. In addition, the groove wall thickness changes can be anywhere on the bobbin so that many types of errors including convergence errors, coma errors and geometry errors, also selective are treatable.

In a preferred embodiment, the grooves are separated from one another by groove walls separated, a thickening in the area of the modified groove wall and possibly on the opposite groove wall have a bulge. This will cause the winding wires forced into their defined, changed position.

Preferred embodiments of the invention are specified in the subclaims.

Fig. 1a einen Ausschnitt eines Spulenkörpers des Standes der Technik mit einem beispielhaft eingewickelten Spulendraht zeigt;

Fig. 1b einen Nutenquerschnitt der Anordnung aus Figur 1a zeigt;

Fig. 2a den Feldverlauf des horizontalen Ablenkfeldes in Z-Richtung angibt;

Fig. 2b den Feldverlauf des vertikalen Ablenkfeldes in Z-Richtung angibt;

Fig. 3a ein horizontales tonnenförmiges Ablenkfeld angibt;

Fig. 3b ein horizontales kissenförmiges Ablenkfeld angibt;

Fig. 3c ein vertikales tonnenförmiges Ablenkfeld angibt;

Fig. 3d ein vertikales kissenförmiges Ablenkfeld angibt;

Fig. 4a einen Ausschnitt eines Spulenkörpers einer erfindungsgemäßen Ablenkeinheit mit zwei beispielhaft eingewickelten Spulendrähten zeigt;

Fig. 4b eine erfindungsgemäß veränderte Nutwand aus Figur 4a zeigt;

Fig. 5 einen Horizontal-Komafehler (g zu rb) verdeutlicht;

Fig. 6 einen Y-Fehler von rb in den Zwischenpunkten verdeutlicht; und

Fig. 7 eine Nord-Süd-Kissenverzeichnung zeigt.

The invention will now be explained in more detail with reference to the accompanying drawings, in which:

1a shows a section of a coil former of the prior art with an example wound coil wire;

1b shows a groove cross section of the arrangement from FIG. 1a;

2a shows the field course of the horizontal deflection field in the Z direction;

2b indicates the field course of the vertical deflection field in the Z direction;

3a shows a horizontal barrel-shaped deflection field;

3b indicates a horizontal pillow-shaped deflection field;

3c indicates a vertical barrel-shaped deflection field;

3d indicates a vertical pillow-shaped deflection field;

4a shows a detail of a coil former of a deflection unit according to the invention with two coil wires wound in by way of example;

4b shows a groove wall from FIG. 4a modified according to the invention;

5 illustrates a horizontal coma error (g to rb);

6 illustrates a Y error of rb in the intermediate points; and

Fig. 7 shows a north-south pillow distortion.

With reference to the accompanying drawings, an embodiment of the Invention explained in more detail.

FIG. 4a shows a section of a coil former according to an embodiment of the present invention. As can be seen from the illustration, the coil body has similar to that of the prior art from FIG. 1a, straight grooves 10, 30, in which the winding wires 40 are inserted. The coil former according to the invention also has 50 thickened or thinned groove walls at selected points, which the inserted winding wires in a deviating from the straight course Force shape. Figure 4b shows the one-sided thickening 50 of the groove wall resulting modified cross section.

By the selective thickening and, if necessary, by one opposite the thickening Bulge, as shown in groove 20 in Figure 4a, the winding wires in forced such a form that an error correction is specifically made possible. In particular local magnetic field inhomogeneities can be generated by the courses the ton fields or pillow fields deviate.

In a preferred embodiment of the invention, the length of the thickening or Bulge along the wound coil wire in the range of a few millimeters to a few centimeters.

Using the example of FIGS. 5 to 7, three of many possible are now special Applications of the invention explained in more detail.

FIG. 5 illustrates a horizontal coma error, which essentially results from this can correct that in the rear area of the deflection unit, the horizontal field is designed pillow-shaped. A targeted error correction can be done according to the invention by changing the groove walls at selected points, to selectively change the angular position of the winding wires at these points.

Figure 6 shows a Y error of the red or blue images, which is essentially a Corrected barrel field in the middle part of the deflection system. A selective fine adjustment is now again achieved according to the invention by groove wall changes, wherein these are to be installed in the middle part of the deflection unit.

Finally, Figure 7 shows a north-south cushion distortion, which is all the more so decreases, the more pillow-shaped the field in the front area of the deflection unit. A Targeted error correction can now be made by changing the groove wall in the front area of the deflection system.

Claims (10)

Deflection unit for mounting on an in-line electron beam tube, comprising a coil former with grooves (10, 20, 30) for receiving wound coil wires (40), the grooves running essentially straight,
characterized in that
the slot wall of at least one slot is changed at at least one point (50) in such a way that the coil wires accommodated in the slot assume a curved course in the region of the changed slot wall. Deflection unit according to Claim 1, characterized in that the grooves are separated from one another by groove walls which have a thickened portion (50) and possibly a bulge in the region of the changed groove profile. Deflection unit according to Claim 1 or 2, characterized in that the coil wires wound on the coil former form a horizontal coil. Deflection unit according to one of Claims 1 to 3, characterized in that the coil wires wound on the coil former form a vertical coil. Deflection unit according to one of claims 1 to 4, characterized in that the groove wall change is carried out to correct convergence errors. Deflection unit according to one of claims 1 to 5, characterized in that the groove wall change is carried out to correct coma errors. Deflection unit according to one of Claims 1 to 6, characterized in that the groove wall change is carried out to correct geometric errors. Deflection unit according to one of Claims 1 to 7, characterized in that the coil former is made of plastic. In-line electron beam tube with a deflection unit according to one of claims 1 to 8th. Screen device comprising an in-line electron beam tube and a deflection unit according to one of claims 1 to 8.

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