DE2840211C2 - Device for setting the convergence and color purity of a color picture tube - Google Patents

Description

30th

The invention relates to a device for adjustment of convergence / and color purity of a color picture tube according to the preamble of the first patent claim.

A device of this type is proposed in the earlier German patent application P 27 22 477.7 been. This device allows. to influence the electron beams on / on. Furthermore it is from DE-OS 26 12 607 and DE-OS 26 11633 known, one in the neck of the tube on the electron beam «ugungssystem fortified permanent magnets to be used with an air gap. Since this ring shares all three electron beams with a relatively large Surrounding circumference, it is not possible with this arrangement, the electron beams individually and substantially to influence independently. This makes convergence segregation considerably more difficult z. B. an outer ray and the central ray already 5 ^ have converged, this outer ray loses wici! its convergence / when the other outer ray is corrected. It is an approximation in many Adjustment steps necessary.

The challenge is based on a To design the device for adjusting convergence and color purity of the type mentioned at the outset in such a way that that an influence of the external electron beams possible regardless of a common horizontal shift of all electron beams is.

The solution to this problem can be found in the characterizing part of the single claim.

This solution also ensures a stable structure of the device.

An exemplary embodiment of the invention is described below with reference to FIGS. I and 2 explained in more detail. It shows F i g. 1 the cessation of convergence,
F i g. 2 the adjustment of the color purity.
1 shows a section through an electron beam generating system arranged in a tube neck 1 at the level of the convergence pot 2 common to the three electron beams R, G. B. The U-shaped permanent magnets 3 and 4 in the horizontal axis 5 and the corresponding permanent magnets 6 and 7 in the vertical axis 8 are inserted with their legs through holes 9 in the wall of the convergence pot 2 and fixed with tabs 10 punched out of the wall of the convergence pot 2 and thus connected to the system in a stable position.

The permanent magnets are magnetized from the outside by the magnetizing device 11.

In the example shown, the right is U-shaped Permanent magnet 3 magnetized so that the legs are in the same direction and the center piece in the opposite direction Have polarity. This will be at the location of the electron beam surrounded by the permanent magnet 3 the legs of the U and the horizontal axis 5 produces approximately parallel Fe'd, which the electron beam in the direction of the vertical axis, in Fig. 1 upwards, deflects.

The legs of the left U-shaped permanent magnet 4 are magnetized with opposite poles. The magnetic field generated thereby runs approximately in the direction of the vertical axis 8 and deflects the electron beam R parallel to the horizontal axis 5 in this example to the right.

With the permanent magnets 3 and 4, it is possible, as described, to move the outer beams R and B independently of one another in the direction of the vertical and horizontal axes and thus to converge them on the central beam.

The permanent magnets 6 and 7 serve to move all three electron beams R. G and B together in the horizontal direction, ie to adjust the color purity. This is illustrated in FIG. The legs of the upper permanent magnet have the opposite polarity as the legs of the lower permanent magnet. This creates a magnetic field in the vertical axis, which jointly deflects the electron beams in the horizontal axis. The mutual distance between the legs of each of the two U-shaped permanent magnets 6 and 7 lying in the vertical axis is chosen so that the same magnetic forces act on all three electronically neutral. In the exemplary embodiment, the distance is shown approximately 40% greater than the mutual distance between the electron beams at this point.

The permanent magnetic metal brackets 3, 4, 6 and 7 are conveniently made from pieces of wire or ribbon material. Of course, the Arrangement also with electronic radiators oval congestion - like geckrueichnei - circular Convergence pots are used '*

1 sheet of drawings

Claims (1)

Claim: Device for setting the convergence and color purity of a color picture tube with three electron guns lying in one plane and a convergence pot common to all three electron beams, with one or more permanent magnets that act on the electron beams and are externally magnetizable to certain values and arranged in the neck of the color picture tube | ₀ whose fields the beams of the three electron guns can be adjusted individually and essentially independently of one another, characterized in that two U-shaped permanent magnets (3, 4) on the _{horizontal axis (5) connecting the three electron beams Vj} and two U-shaped permanent magnets ( 6, 7) are attached to the convergence pot (?) On the vertical axis (8) passing through the central electron beam (G) in a plane perpendicular to the central electron beam (G) so that the webs of the U-shaped permanent magnets connecting the legs (3, 4, 6, 7) rest on the convergence pot (2), and that the mutual spacing of the legs of each of the two U-shaped permanent magnets (6, 7) lying in the vertical axis is selected so that all three 7. Electron rays (R, G, compensate magnetic forces act.