DE2822345A1 - METHOD AND APPARATUS FOR MANUFACTURING A COLOR TELEVISION TUBE - Google Patents

Description

PHILIPS PATENTVERWALTUNG GMBH, STEINDAMM 94, 2000 HAMBURG 1

Method and apparatus for manufacturing a color television picture tube

The invention relates to a method for producing a color television picture tube, in which, inter alia, in a front glass that simultaneously acts as a recording jig with the open side up and on its inner surface first a spacer jig, on this a masking plate and then a support frame of a color selection electrode to be formed with its inserted into the brackets that can be snapped into place in the front glass and then the mask plate bent at the edge by machine at the overlapping points by spot welding after the mask plate has been adjusted in relation to the support frame
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is attached to these, and will continue to do so in a later date In the process step, the color selection electrode with its holders is snapped into the front glass in three places Distance gauge is missing, and after adjusting at three points at the fourth so-called south point, the holding plate for the fourth holder is welded on, which continues in later process steps with so-called flow coating and also after the final assembly the color identification electrode each with its four holders inserted into the front glass and in this for the purpose of exposure or to achieve the correct one final position relative to the screen is adjusted.

The invention also relates to a device for Carrying out the above method of manufacturing a color television picture tube.

In a method of manufacturing a color television picture tube and with the devices used for this process, one of the most critical process steps is with the Associated devices intended to maintain the distance between the color selection electrode and the front glass during the manufacturing process with very low tolerances.

The introduction of the so-called in-line technology, in which the three electron guns are attached next to each other in one plane and no longer as with the Delta tube on the corner points of an isosceles triangle, and the resulting new coating of the screen no longer with fluorescent material arranged on the corners of an isosceles triangle, but with fluorescent material lying in the direction of the image Fluorescent strips with alternating colors, namely the colors red, green and blue, with the order in the individual manufacturers are also different for different reasons, brought a certain relief, because the tolerances for the point of impact of the electron beam on the screen are somewhat expanded in the direction of the image could be. However, in the direction of the line, the tolerances PHD 78-065 - 6 -

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continue to exist, so that during the manufacturing process just when assembling the color selection electrode and later during the manufacturing process in the various process stages of the position of the color selection electrode the greatest attention had to be paid to the front glass.

With the recently introduced increase in the brightness of the image, the requirements for the accuracy of the electron beam have been increased further increased on the associated fluorescent strip. This made the allowable tolerances in the distance between the inner surface of the front glass and the outer surface of the hash plate, further narrowed, what one more higher accuracy of insertion of the color selection electrode in daqi * ront glass made necessary.

In such work there are numerous so-called adjustment steps required, with certain adjustment aids being attached to the machines in order to keep the parts as close as possible to one another align. So it is known in a fairly early process step, the front glass in the machine in such a way insert so that the support frame with the brackets attached to it can be inserted from above, e.g. the Balter May have bores that grip over corresponding mandrels inserted in the glass and snap into place there. This one only The support frame provided with the holders is then placed in the machine on the pre-bent hash plate that is already in front of the support frame was placed on a spacer gauge, which in turn rests on the inner surface of the front glass, which is open at the top, in placed in the most precise position possible and welded to the hash plate on the defang. It turned out, that in many cases the support frame was not quite correctly held in the front glass, namely because the holder is not quite on the Pushing on the mandrels and thereby a slight misalignment was possible. As a result, it could happen that the hask plate opposite the support frame was also not placed correctly and then welded in a slightly inclined position. PHD 78-065 - 7 -

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In a much later process step, the so-called South point is determined, i.e. the finished color selection electrode is placed in a corresponding device from above latched into the front glass at three points with the holders and then usually pressed down by hand so that it clicks into place. The distance can then be determined in this position. But it will definitely be special Process step of the south point determined by the fact that a retaining plate is in the locked state of the color selection electrode is welded in the front glass for the fourth holder. This additional welding gives the color selection electrode greater mechanical stability. For this, too, it is necessary that the color selection electrode with its holders sits correctly on the thorns, and if the thorns are a little rough, the holders sometimes do not slide properly over the Mandrels, so that the suggestion was made to polish the mandrels and drill the corresponding holes in the Holders easy to punch conically, so that a better pushing was guaranteed. Such work steps are but very expensive in mass production.

It was also found that with so-called flow coating, that is, with the individual exposures for the colors red, green and blue, the latching of the color selection electrode at the four points with the four holders in the front glass not with the sufficient accuracy. Here differences from worker to worker were noticeable, because namely the different imagesetters worked with quite different degrees of care and therefore fluctuations in the tolerances to be observed were detectable.

Finally, there was the final insertion of the color selection electrode Particular care is required in the front glass before assembling the tube, because that too The last work step was one of the decisive factors in how the electron beam was later in the fully assembled tube of a generation system its assigned luminous PHD 78-065 - 8 -

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strips of fabric meets. While in the center of a screen hardly any deviations occurred, but strong deviations were visible in the direction of the diagonal near the corners, so that it was necessary to intervene decisively here.

The general state of the art includes vibrating tables, e.g. for establishing loose contacts in the manufacture of electronic devices Circuits or vibrating conveyors are known, e.g. in the production of electronic components for belting. In the art of manufacturing color television picture tubes, it has also been known to shake the tube piston around loose parts to shake out of the mask area so that they do not interfere in the reproduced image, with loose parts in the Form of weld splatters, glass splinters or organic substances could occur, all of which, if they lay down in front of the slot in the color selection electrode, a clear shadow or color falsifications on the Screen caused by the operation of the color television picture tube, so that such a tube when the part is not shaken could be eliminated, was not for sale.

Tubes with color purity errors caused by the above-mentioned not completely one hundred percent adjustment in the various Procedural steps caused were later difficult to correct.

The object of the invention thus consisted in a method for producing a color television picture tube Introduce procedural steps in order to achieve a higher level of accuracy.

To achieve this object, in a method for producing a color television picture tube, the method mentioned at the outset is used Kind according to the invention as EinJustierhilfe an application of a changing magnetic field in such a way that the parts moved thereby are brought into their desired exact position. The invention thus consists in, inter alia, in the initially mentioned PHD 78-065 - 9 -

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suggested procedures to introduce additional procedural steps at the relevant points, i.e. a changing one To make the magnetic field effective, causing the parts to shake. Achieve by shaking it like this the parts have a defined end position, so that a reliable further assembly then takes place in the next process step can, with the result that the position of the parts when adjusting by the worker on the machine in question or device became independent and that a narrowing of the tolerances was also possible.

A device for carrying out the method according to the invention is characterized in that for adjustment the support frame with its holders in the front glass and the Mask plate opposite the support frame in the manufacture of the color selection electrode outside of the front glass or a plurality of electromagnets which can be excited with alternating current of 50 Hz are arranged in this way on the middle of the sides of the support frame are that their magnetic poles are in the circumferential direction, that their magnetic field lines run predominantly perpendicular through the raised edge of the front glass to the support frame and are arranged so close to the support frame that the vibrating field magnetically generated by the electromagnets the parts brings it to its final position in about 5 seconds.

Another device for carrying out the method according to the invention is that for adjusting the color selection electrode at three points before the fastening of the holding plate for the holder at the south point, two electromagnets which can be excited with alternating current of 50 Hz, for example on the two south corners of the support frame outside the front glass are arranged so that their magnetic poles are in the circumferential direction, that their magnetic field lines run predominantly perpendicular through the raised edge of the front glass to the support frame and are so close to the support frame that the vibrating field magnetically generated by the electromagnets push-pull the parts in about 5 seconds brings its final location.
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P 28 22 345.2 Hamburg, June 7, 1978

Philips patent administration GüibH Zr / gü

New page 10:

Finally, a device for performing the method according to the invention can be characterized in that for adjusting the color selection electrode on its four holders before the individual exposures during so-called flow coating two electromagnets that can be excited in push-pull with alternating current of 50 Hz with their poles in the circumferential direction below the front glass near the raised edge and near the corners of the front glass or the support frame are arranged perpendicular to the line direction or image direction in such a way that their magnetic field lines predominantly run perpendicular to the support frame, and are arranged so close to the support frame that the electromagnet Magnetically generated vibrating field brings the parts into their final position in about 5 seconds.

Alternatively, at least two electromagnets on the spherical side of the front glass in the area above the Be arranged support frame.

When using the invention, for example, accuracy of insertion can be achieved in the axial direction of the distance between the mask plate and the inner surfaces of the front glass from 0.01 to 0.02 mm are adhered to. The improvements are compared to manual insertion e.g. when fixing the south point up to 20 / um.

Embodiments of the invention are shown in the drawing and are described in more detail below. It demonstrate

Fig. 1 is a plan view of the raised edge of a front glass with inserted color selection electrode and an electromagnet on the long side,

Fig. 2 is a cross-sectional view of the critical suspension points, namely storage of the bore of a holder of the color selection electrode on a mandrel and support of the mask plate on a support frame,

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3 shows a plan view of the raised edge of a front glass with a color selection electrode inserted therein and two electromagnets according to the invention on the two narrow sides,

4 shows a plan view of the front glass with two attached electromagnets in the spherical area,

FIG. 5 shows the side view of FIG. 4 in a partially sectioned illustration with two alternatives for the position of the Electromagnets,

6 shows an example of a circuit arrangement for the connections of two electromagnets.

In the figures, 1 denotes the raised edge of the front glass of a color television picture tube. In Fig. the suspension points for a support frame 3 with masking plate 4 of a color selection electrode are designated at 2, wherein this color selection electrode, which is generally provided with the reference numeral 5, in a device in a respective one Machine is inserted into the front glass from above. The front glass should be inserted so that after the open side is on top. The three holders are locked into place at 2, and thus the inserted support frame 3 with it its holders snaps into place at 2, and the mask plate finds its correct position, the electromagnet 16 is switched on. It exerts a pull on the support frame via the magnetic field. The field lines of the electromagnet 16 emerge from the with N and S marked poles approximately perpendicular, as indicated at 8, then run to the support frame and close in If the electromagnet 16 is connected to the AC power supply at 50 Hz, the support frame will vibrate with 100 Hz and thus this is shaken up with its holders on the mandrels and without the intervention of a worker the final position is reached after about 5 seconds. At the same time, the mask plate 4 is shaken into its force-free rest position. Only then does the machine release welding for the mask plate.

The automatic welding takes place at 14 (Fig. 2) on the circumference at the overlapping areas of the bent edge

PHD 78-065 OnPfiAft / miö -Continued on p. 12 of the origin- »Uööifö / öilB borrowed documents from. 5/22/78-

from the mask plate 13 to the opposite part of the support frame

For the sake of clarity, such a holder is again shown schematically in FIG. 2. Thus, Fig. on the left at 9 a part of the raised edge of the front glass. 10 is the metallic one inserted into the glass Mandrel on which holder 11 rests. This holder is welded to the support frame 12 of the color selection electrode and carries at one end a hole which is pushed over the conical part of the dome. This leaves the color selection electrode Always detachable in the front glass during production and can only be removed later by the spring force of the holder 11 held. The support frame 12 can be thicker-walled than the mask plate. He doesn't need it for so-called frameless Masks. It is common to provide the sheet metal 12 with beads and thereby an equal sheet thickness from the mask sheet 13 to Transfer frame 12, which is for thermal reasons is very cheap. The connection between the support frame 12 and the masking plate 13 takes place at 14. It is easy to see that for making the connections 14, which are up to 10 spot welds on the circumference for a 67 cm color television picture tube is, the support frame 12 with its holder 11 must first of all rest properly on the mandrel 10, and although in a final position. Then the sheet 13 must correctly on the support frame 12 or on the raised edge 12 of the Place the color selection electrode in order to make the weld at 14 in the correct assignment of the parts. So now on the correct position is reached in both places, the electromagnet 16 is switched on in a certain procedural stage and then shakes, whereby the 100 Hz vibration can last about 5 seconds. Then the parts have theirs correct position is reached and the next process step can take place.

Fig. 3 shows another similar arrangement. In a later process step, the so-called To define the south point, i.e. at the three points marked with 2, the color selection electrode 5 is in the raised one PHD 78-065 - 13 -

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The edge of the front glass 1 is locked into place. Only the so-called south point at 15 is free. It becomes the electromagnets here and 7 switched on. You bring the entire color selection electrode compared to the stationary glass in vibration with / 50 Hz and also after about 5 seconds here is a final position reached and the person working at this workplace can use the holding plate to attach the holder for the south point weld on, so that the last point for the attachment of the color selection electrode in the relevant associated Front glass is set and fixed.

Adjustment by hand was also provided at this point so far, with the different fitters being different Applying pressure to the color selection electrode and thereby achieving different results in manufacturing became.

4 shows a further arrangement in an even later method stage. The top view of the front glass 1 is shown, namely on the spherical part on which the screen is deposited on the inside. When storing the As is well known, the screen is worked in three exposure steps in so-called flow coating, because the colors Red, green and blue have to be applied one after the other in separate steps, because namely for exposure the Light source must take different positions. Included

If fluorescent ions and water must be used in this chemical treatment process, the color selection electrode 5 must be removed from the front glass each time during the treatment. It is unhooked from the holders 2 and re-engaged before the next exposure step, the mask again being correctly pressed into the holder by hand. This results in considerable differences in the position of the color selection electrode, and in order to be independent of this manual work, according to the invention on the spherical part or below the front glass, as shown in FIGS. 5 and 4, on one side of the front glass or the Support frame 3, two electromagnets are placed, the fields of which are PHD 78-065 - 14 -

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meet perpendicular to the support frame and in this conclude. If at least two electromagnets 17 and 18 are arranged, then there is a shaking, which is sufficient to bring the parts into their exact position each time. Alternatively, electromagnets 19 and 20 can be used below the The support frame must be arranged, i.e. on the open side of the front glass, here too, precise positioning is always required of the parts against each other and thereby significantly improves the tolerances in manufacture.

Finally, FIG. 6 shows an example circuit arrangement. The AC mains can be connected to terminals 21 and 22 connected with 220 V / 50 Hz. An adjustable transformer has outputs that are fed to the rectifiers 24 and 25 Electromagnets 6 and 7 lead. These are therefore excited in phase opposition and thereby pull the sheet metal or the ferromagnetic one Iron the support frame towards you, and that in a cycle of 50 Hz, so that the parts vibrate and through the fine vibration in be shaken into the correct position.

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Claims (6)

PHILIPS PATENT ADMINISTRATION GIIBII. STEINDAMM 94, 2000 HAMBURG 1 PATENT CLAIMS; \1. J Process for the production of a color television picture tube, in which, among other things, in a front glass that simultaneously acts as a recording jig with the open side up and on its inner surface first a spacer gauge, on this a masking plate and then a support frame of a color selection electrode to be formed with its in the front glass Mandrels snap-in holders are inserted and then the mask sheet, which is bent over at the edge, is mechanically fastened to the overlapping points by spot welding after the mask sheet has been adjusted in relation to the support frame, in which the color selection electrode with its holders in the front glass at three points continues in a later process step is locked, the distance gauge is missing, and after adjusting at three points at the fourth so-called south point, the retaining plate for the fourth holder is welded, which continues in later process steps with so-called flowcoating and auc h after the final assembly, the color selection electrode with its four holders is placed in the front glass and adjusted in this for the purpose of exposure or to achieve the correct final position relative to the screen, characterized in that a changing magnetic field is used as an adjustment aid, that the parts moved thereby are brought into their desired exact position. 2. Apparatus for performing the method according to claim 1, characterized in that for adjusting the Support frame with its holders in the front glass and the mask plate opposite the support frame during manufacture of the color selection electrode outside the front glass, an electromagnet in the middle that can be excited with an alternating current of 50 Hz the longitudinal side of the support frame is arranged such that its magnetic poles are in the circumferential direction that their magnetic Field lines run predominantly perpendicular through the raised edge of the front glass to the support frame and so close to the PHD 78-065 - 2 - 909843/0113 ORIGINAL INSPECTED Support frame are arranged that the vibrating field magnetically generated by the electromagnet, the parts in about 5 see in brings its final location. 3. Apparatus for performing the method according to claim 1, characterized in that for adjustment the color selection electrode at three points before the attachment of the holding plate for the holder at the south point two with alternating current 50 Hz excitable electromagnets in the vicinity of the southern corners of the support frame outside of the front glass are arranged in this way are that their magnetic poles are in the circumferential direction, that their magnetic field lines predominantly perpendicular through the raised Edge of the front glass, run to the support frame, and are arranged so close to the support frame that the through Electromagnets magnetically generated vibrating field brings the parts into their final position in about 5 seconds. 4. Apparatus for performing the method according to claim 1, characterized in that for adjusting the Color selection electrode on its four holders before the individual exposures in the so-called flowcoating with at least two Alternating current of 50 Hz excitable electromagnets with their poles in the circumferential direction lying outside the front glass on the so-called spherical part of the same near the raised edge and near the corners of one Side of the front glass or the support frame are arranged lying in the line direction and / or image direction in such a way that their magnetic field lines run predominantly perpendicular through the glass of the front glass to the support frame and such are arranged close to the support frame that the vibrating field magnetically generated by the electromagnets the parts in brings about 5 see into its final position. 5. Apparatus according to claim 4, characterized in that at least two electromagnets on the open side of the front glass are arranged in the area below the support frame. PHD 78-065 - 3 - 809848/0118 6. Device according to one or more of the preceding claims, characterized in that the pole spacing of the electromagnets approximately equal to the sum of the glass thickness and the required distance between the inner surface of the front glass and the outer surface of the mask sheet is the color selection electrode. PHD 78-065 -U- 909848/0118