JPS6131937B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In manufacturing a color television display tube having a color selection electrode, the present invention provides a method for attaching the color selection electrode to be formed in at least one step or the completed color selection electrode to the face plate by its holder. The present invention relates to a method of manufacturing a color television display tube including supporting on at least three support pins present within the color television display tube.

One of the most important steps in the manufacture of color television display tubes is maintaining the spacing between the color selection electrodes and the faceplate to very close tolerances during manufacture.

Instead of arranging three electron guns at the vertices of an equilateral triangle like in a delta array tube, they are arranged side by side in one plane,
The introduction of so-called in-line technology has made production easier, in which instead of coating the display screen with an equilateral triangular array of fluorescent dots, it is now possible to coat the display screen with fluorescent strips of different colors, namely red, edge and blue, extending in the direction of the frame. It got easier. This is because the tolerance for the landing point of the electron beam on the display screen can be made slightly larger in the frame direction. but,
It is still necessary to maintain extremely close tolerances in the line direction, which requires paying the greatest attention to the position of the color selection electrode relative to the faceplate, especially during the assembly of the color selection electrode and during the various subsequent manufacturing steps. There is.

In order to further increase the currently achieved brightness, it is necessary to further increase the precision of the landing of the electron beam onto the relevant fluorescent strip. As a result,
Tighter tolerances on the spacing between the inner surface of the faceplate and the outer surface of the mask sheet are required, and therefore the color selection electrodes need to be provided within the faceplate with greater accuracy.

For this purpose, several so-called adjustment steps are necessary, and the assembly machine is equipped with adjustment means for aligning the various parts with respect to each other as precisely as possible. For example, in the early stages of manufacturing, the face plate is placed in a machine such that a support frame fitted with a holder provided with holes that snap into support pins provided in the glass face plate can be inserted from above, and then The support frame with the holder is inserted into the machine and, before its insertion, is placed as precisely as possible onto the mask sheet which is placed on the spacing jig placed on the inner surface of the face plate which is open at the top. The frame is then welded to the periphery of the mask sheet. However, it has been found that in this case, the holder is not completely snapped onto the support pins, so that the support frame is not properly retained within the faceplate and is often placed in a slightly tilted position. As a result, the mask sheet may not be properly placed on the support frame and may be welded in a slightly tilted position.

In a further later step, so-called south point fixation is performed. That is, the completed color selection electrode is inserted from above into the faceplate in a suitable device and the holder is snapped onto the three support pins, usually by hand. The spacing can be predetermined at this location. However, fixing the south point is done in a separate step in which the retaining plate for the fourth holder is welded to the color selection electrode that is snapped into the face plate. As a result of this additional welding, the color selective electrode is more mechanically stable. For this purpose, it is necessary to correctly position the color selection electrode on the support pin of the holder, and even if the support pin has a slightly rough surface, the holder will not slide correctly on the support pin, so the support pin must be polished and the holder must be properly positioned. It has been suggested that the holes be slightly conical in order to provide good sliding. However, these measures are extremely expensive in continuous production.

Furthermore, in the so-called flow coating process, the color selection electrode must be inserted into and removed from the face plate by snapping its four holders and four support pins each time each red, green, and blue phosphor is exposed. However, it has been confirmed that this cannot be done with sufficient precision. There are individual differences among each operator, and the various exposures are performed with different precision, resulting in differences in manufacturing tolerances.

Finally, special attention should be paid to the final positioning of the color-selective electrodes in the faceplate before tube assembly, as this will determine how the finished tube's electron beam will land on its associated phosphor strip. is necessary. As a result, almost no deviation occurs in the center of the display screen, but a considerable deviation occurs in the diagonal direction near the corners, so special measures are required.

BACKGROUND OF THE INVENTION Vibrating tables for reliably contacting imperfect contacts in the production of electronic circuits, for example, or vibratory transport devices for transporting electronic components in the production of electronic components are known from the prior art. It is known in the art of manufacturing color television to vibrate the tube in order to shake loose particles out of the mask area so that these particles do not interfere with the displayed image. occur in the form of organic substances, and these particles, if stuck in front of the slot of the color selection electrode, will cause distinct shadows or color defects on the display screen during operation of the color television display tube, and these particles cannot be removed. (Otherwise, the tube becomes unsaleable.) Tubes with color purity gaps due to imperfect alignment in some of the manufacturing processes described above are extremely difficult to correct later.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to introduce a process suitable for achieving good precision into a color television manufacturing method.

In order to solve this problem, the present invention provides a method for manufacturing a color television display tube described in the first paragraph of this column, in which each part of the color selection electrode is vibrated using an alternating magnetic field as a position adjustment means. It is characterized by moving parts to their correct positions. That is, the present invention is a method for manufacturing a color television display tube described in the first paragraph of this column, in which a step of applying an alternating magnetic field to vibrate each component is added. As a result of such vibrations, each part settles into a defined final position, which ensures subsequent assembly in the next step, and the position of the parts due to the above adjustment is independent of the operator of the machine or equipment. , tighter tolerances are possible.

In the method of the present invention, when adjusting the position of the support frame supported in the face plate by the holder and when adjusting the position of the mask sheet with respect to the support frame during the production of color selection electrodes, an alternating current-driven one is used.
One or more electromagnets are placed outside the face plate in the center of the sides of the support frame so that the oscillating magnetic field generated by the electromagnets moves the parts to their final position in about 5 seconds.

In the method of the present invention, in order to adjust the position of the color selection electrode supported at three points before connecting the retaining plate for the south point holder, two
Electromagnets are placed near the south corner of the support frame and outside the upright edges of the face plate so that the oscillating magnetic field generated by the electromagnets moves the parts to their final positions in about 5 seconds.

Furthermore, in the method of the present invention, four steps are performed before each exposure process in the so-called flow coating process.
To adjust the position of the color selection electrode supported by the holder, two electromagnets that can be driven by alternating current are placed in a line (horizontally) below near the upright edge of the corner of the face plate.
or frame (vertical) orientation such that the oscillating magnetic field generated by these electromagnets moves the parts to their final position in about 5 seconds.

Alternatively, at least two electromagnets can be provided on the spherical side of the face plate in the upper area of the support frame.

These electromagnets are preferably excited with an alternating current of approximately 50 Hz.

By using the present invention, the insertion accuracy of the axial distance between the mask sheet and the inner surface of the face plate can be maintained at 0.01 to 0.02 mm. This is a considerable improvement over manual work, for example when fixing the south point the tolerance is 20μ.
It was less than m.

The invention will be explained with reference to the drawings.

In each figure, 1 indicates the upright edge of the face plate of a color television display tube. In FIG. 1, reference numeral 2 indicates a support point of the support frame 3 of the mask sheet 4 of the color selection electrode. This color selection electrode (the whole is indicated by 5)
is inserted from above into the face plate 1 in the associated machine.
Therefore, it is necessary to insert the face plate 1 so that its opening side faces upward. Support point 2 for 3 holders
and switch on the electromagnet 16 to determine the correct position of the support frame 3 and the mask sheet snapped onto the support point 2 with the holder. The electromagnet 16 exerts an attractive force on the support frame by its magnetic field. The magnetic field lines of electromagnet 16 emanate generally perpendicularly from magnetic poles N and S, as shown at 8, and then extend along and close within the support frame. When the electromagnet is connected to a 50Hz AC power supply, the support frame vibrates at 100Hz, and the holder of the support frame is therefore rocked on the support pins and reaches its final position after about 5 seconds without any intervention from the operator. It subsides. At the same time, the mask sheet 4 is also shaken and settled into its stress-free rest position. After this, the machine starts the welding process of the mask sheet 4.

Automatic welding is performed at the overlapped portion of the folded edge 13 of the mask sheet and the opposing portion of the support frame 12, as shown at 14 in FIG.

Also shown in FIG. 2 is a holder. On the left side of FIG. 2, 9 indicates the upright edge of the face plate. Reference numeral 10 indicates a metal support pin molded into the glass of the face plate, on which the holder 11 is supported. This holder is welded to the support frame 12 of the color selection electrode and has a hole at one end that fits into the cone of the support pin. As a result, the color selection electrode is removably held within the face plate during manufacture, and is held only by the elasticity of the holder 11 after manufacture. The support frame 12 may be thicker than the mask sheet. This is necessary in the case of so-called frame masks. Usually mask sheet 1
3 is provided with a reinforcing material, and the mask sheet 13 and frame 12 are made to have the same sheet thickness. In this case, thermal conditions are also extremely favorable. The support frame 12 and the mask sheet 13 are connected by 14. This concatenation (67
In order to perform welding at 10 points along the periphery of a cm color television display tube, it is first necessary to properly position the support frame 12 with the holder 11 on the support pins. It is then necessary to precisely position the mask sheet 13 over the support frame 12, ie the upright edges 12 of the color selection electrodes, and weld both parts in place. To achieve the above two correct positions, the present invention switches on the electromagnet 16 in a given step to vibrate these parts at 100 Hz for about 5 seconds. In this case these parts are in their correct position and the next step can be carried out.

FIG. 3 shows another similar arrangement of the invention, which is particularly relevant to the fixation of the south point which is carried out later in the manufacturing process. That is, the color selection electrode is snapped onto the upright edge of the face plate 1 at three points, indicated at 2, leaving only the so-called south point, indicated at 15, free. When the electromagnets 6 and 7 are switched on, these electromagnets vibrate the entire color selection electrode against the fixed glass face plate at a frequency of 50 Hz, and in this case also settle into the final position after about 5 seconds, allowing the operator to hold the holder for connection. The last point of the color selection electrode can be secured in the face plate by welding the plate to the south point.

Conventionally, position adjustment was performed manually in this step as well, so different pressures were applied to the color selection electrodes by individual operators, resulting in variations in manufacturing results.

FIG. 4 shows the arrangement in a later step. FIG. 4 is a plan view of the spherical side of the face plate 1 (ie, the display screen faces inward). In the so-called flow coating process, the display screen is placed facing downwards and three exposure steps are performed as is known. That is, the red, green and blue phosphors are sequentially applied in separate steps, with the light source at a different location for each exposure. Since this chemical treatment requires the use of a fluorescent suspension and water, it is necessary to remove the color selection electrode 5 from the face plate each time. That is, the color selection electrodes 5 are removed from the support pins, and before the next exposure step, they are snapped together again and the mask is manually fitted into the support pins correctly. At this time, a significant displacement of the color selection electrode occurs. In the present invention, in order to eliminate the above-mentioned manual work, two electromagnets are provided on one side of the face plate and support frame 3 on the spherical part of the face plate or below the face plate, and the magnetic field of these electromagnets hits the support frame at right angles. , so that it closes within the supporting frame. at least two electromagnets 17 and 1
8 will generate enough vibration to move each member into the correct position. The electromagnets 19 and 20 can also be provided below the support frame, ie on the open side of the face plate. In this case as well, correct positioning of the individual parts is always achieved, so that tolerances during manufacture are significantly improved.

Finally, FIG. 6 shows an example of an electromagnet circuit.
Terminals 21 and 22 can be powered from a 220V/50Hz AC power supply. The output of the adjustable transformer 23 is conducted to the electromagnets 6 and 7 via rectifiers 24 and 25. For this reason, these electromagnets are energized in opposite phases and attract the ferromagnetic iron of the mask sheet and support frame at 50 Hz, so that these parts vibrate and move into their correct position due to this micro-vibration.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the electromagnet used in the method of the present invention arranged along the upright edge of the face plate into which the color selection electrode is inserted and its long side edge, and FIG. 2 is a cross section of the support point of the color selection electrode. Figure 3 is a plan view showing the two electromagnets used in the method of the invention arranged along the upright edge and two short edges of the face plate into which color selection electrodes are inserted, and Figure 4 shows the face plate. FIG. 5 is a sectional view taken along the - line of FIG. 4, and FIG. 6 is an example of a connection circuit for the two electromagnets. It is a circuit diagram. 1, 9... Upright edge of face plate, 2... Support point, 3...
...Support frame, 4...Mask sheet, 5...Color selection electrode, 10...Support pin, 11...Holder,
12...Support frame, 13...Mask sheet,
14...Welding point, 15...South point, 6,7,16,
17, 18, 19, 20...electromagnet.

Claims (1)

[Scope of Claims] 1. At least three supporting frames for color selection electrodes to be formed in at least one manufacturing process or for holding completed color selection electrodes on a drawing board by means of their holders.
A method for manufacturing a color television display tube having a color selection electrode with support on support pins for moving said parts using a varying magnetic field as a position adjustment means to bring these parts into their correct position. A method for manufacturing a color television display tube, characterized in that: 2. In the method according to claim 1, when adjusting the position of the support frame supported in the face plate by the holder and when adjusting the position of the mask sheet with respect to the support frame during the manufacture of the color selection electrode, One or more driveable electromagnets are placed outside the face plate in the center of the sides of the support frame so that the oscillating magnetic field generated by the electromagnets moves the parts to their final position in about 5 seconds. A method for manufacturing a color television display tube, characterized in that: 3 In the method according to claim 1, when adjusting the position of the color selection electrode supported at three points before connecting the retaining plate for the south point holder, two electromagnets that can be driven by alternating current are supported. A color television, characterized in that said parts are arranged outside the upright edge of the face plate near the south corner of the frame so that the oscillating magnetic field generated by these electromagnets moves said parts to their final positions in about 5 seconds. A method for manufacturing a display tube. 4. In the method according to claim 1, when adjusting the position of the color selection electrodes supported by four holders on each exposure side in the so-called flow coating process, at least two electrodes that can be driven by alternating current are used. Electromagnets are placed in the line direction and/or in the frame direction on the so-called spherical portion of the face plate near the upright edges of the face plate and near the corners of one side of the face plate and support frame, and the oscillating magnetic field generated by these electromagnets causes the component to be moved. A method for manufacturing a color television display tube, characterized in that the tube is moved to its final position in about 5 seconds. 5. A method for manufacturing a color television display tube according to claim 4, characterized in that at least two electromagnets are arranged on the open side of the face plate in the area below the support frame. 6. A method for manufacturing a color television display tube according to any one of claims 1 to 5, characterized in that the electromagnet is excited with an alternating current of about 50 Hz.