CA1145813A - Method of manufacturing a colour television display tube - Google Patents
Method of manufacturing a colour television display tubeInfo
- Publication number
- CA1145813A CA1145813A CA000327937A CA327937A CA1145813A CA 1145813 A CA1145813 A CA 1145813A CA 000327937 A CA000327937 A CA 000327937A CA 327937 A CA327937 A CA 327937A CA 1145813 A CA1145813 A CA 1145813A
- Authority
- CA
- Canada
- Prior art keywords
- face plate
- supporting frame
- mask
- frame
- time
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
- H01J29/06—Screens for shielding; Masks interposed in the electron stream
- H01J29/07—Shadow masks for colour television tubes
- H01J29/073—Mounting arrangements associated with shadow masks
Landscapes
- Electrodes For Cathode-Ray Tubes (AREA)
- Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
- Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
Abstract
ABSTRACT.
"Method of manufacturing a colour television display tube".
In various steps of the method of manufacturing a colour television display tube, parts have to be aligned exactly with respect to each other, for example, alignment of the mask sheet with respect to the mask supporting frame during the manufacture of the colour selection electrode, alignment of the colour selection electrode in the face plate during the connection of the holding plate in the south point, furthermore several times laying down the colour selection electrode in the face plate during the three exposures for providing the phosphors of different colours. In most of the above-mentioned cases the "seating"
of the parts was endeavoured by manual pressure, considerable differences being the result. By the use of electromagnets which are energized with an alternating voltage and by which magnetic attractive forces are exerted on the parts, the parts are vibrated to their position in a few seconds.
"Method of manufacturing a colour television display tube".
In various steps of the method of manufacturing a colour television display tube, parts have to be aligned exactly with respect to each other, for example, alignment of the mask sheet with respect to the mask supporting frame during the manufacture of the colour selection electrode, alignment of the colour selection electrode in the face plate during the connection of the holding plate in the south point, furthermore several times laying down the colour selection electrode in the face plate during the three exposures for providing the phosphors of different colours. In most of the above-mentioned cases the "seating"
of the parts was endeavoured by manual pressure, considerable differences being the result. By the use of electromagnets which are energized with an alternating voltage and by which magnetic attractive forces are exerted on the parts, the parts are vibrated to their position in a few seconds.
Description
1:145813 1 PHD. 78-065.
The invention relates to a method of manufac-turing a colour television display tube having a colour selection electrode in which in at least one step of the method a supporting frame of a colour selection elec-trode must be accurately positioned on at least threemandrels present in the face plate of the tube.
During the manufacture of a colour television display tube one of the most critical steps is establish-ing the spacing between the colour selection electrode and the face plate with very small tolerances.
The introduction of the so-called In-Line tech-nique in which the three electron gun systems are arranged in one plane beside each other and luminescent strips having alternating colours are formed on the screen provided a certain relaxation of tolerances, because in the direction of the strips the tolerances for the landing point of the electron beam on the display screen could be slightly widened. However, in the direction of the raster scan lines the tolerances remained so that during tube manufacture, and especially during assembly of the colour selection electrode, utmost care must be taken when positioning the colour selection electrode with respect to the face plate.
With the increase in brightness introduced recently, the requirements on the landing accuracy of the electron beams on thP associated luminescent strips were further increased. As a result of this, the permissible tolerances in the distance between the inner surface of 1~45813
The invention relates to a method of manufac-turing a colour television display tube having a colour selection electrode in which in at least one step of the method a supporting frame of a colour selection elec-trode must be accurately positioned on at least threemandrels present in the face plate of the tube.
During the manufacture of a colour television display tube one of the most critical steps is establish-ing the spacing between the colour selection electrode and the face plate with very small tolerances.
The introduction of the so-called In-Line tech-nique in which the three electron gun systems are arranged in one plane beside each other and luminescent strips having alternating colours are formed on the screen provided a certain relaxation of tolerances, because in the direction of the strips the tolerances for the landing point of the electron beam on the display screen could be slightly widened. However, in the direction of the raster scan lines the tolerances remained so that during tube manufacture, and especially during assembly of the colour selection electrode, utmost care must be taken when positioning the colour selection electrode with respect to the face plate.
With the increase in brightness introduced recently, the requirements on the landing accuracy of the electron beams on thP associated luminescent strips were further increased. As a result of this, the permissible tolerances in the distance between the inner surface of 1~45813
-2- PH~. 78-065.
the face plate and the outer surface of the mask sheet were further restricted, which necessitated an even higher accuracy of the position of the colour selection electrode in the face plate.
During tube manufacture, several adjusting steps are performed to align the parts as accurately as possible with respect to each other. For example, in an early step of a known manufacturing process a supporting frame with holders connected thereto is inserted into the face plate.
The holders typically include apertures which snap into engagement with corresponding mandrels provided in the face plate glass. This supporting frame is then welded to a pre-bent mask sheet which is positioned as accurately as possible, which sheet had been laid on a spacing jig placed on the inner surface of the face plate before the supporting frame was inserted. It has been found that the supporting frame was often not held correctly in the face plate during welding because the holders had not been placed firmly on the mandrels. As a result the mask sheet would not be correctly positioned on the supporting frame and would be welded in a slightly oblique position.
In a much later step of the tube manufacturing process the finished colour selection electrode,compris-ing the suppor*ing frame and mask sheet,is inserted into the face plate and the holders are snapped into engage-ment with the mandrels. An additional holder is then snapped onto a respective face plate mandrel and this holder is also welded to the supporting frame. This
the face plate and the outer surface of the mask sheet were further restricted, which necessitated an even higher accuracy of the position of the colour selection electrode in the face plate.
During tube manufacture, several adjusting steps are performed to align the parts as accurately as possible with respect to each other. For example, in an early step of a known manufacturing process a supporting frame with holders connected thereto is inserted into the face plate.
The holders typically include apertures which snap into engagement with corresponding mandrels provided in the face plate glass. This supporting frame is then welded to a pre-bent mask sheet which is positioned as accurately as possible, which sheet had been laid on a spacing jig placed on the inner surface of the face plate before the supporting frame was inserted. It has been found that the supporting frame was often not held correctly in the face plate during welding because the holders had not been placed firmly on the mandrels. As a result the mask sheet would not be correctly positioned on the supporting frame and would be welded in a slightly oblique position.
In a much later step of the tube manufacturing process the finished colour selection electrode,compris-ing the suppor*ing frame and mask sheet,is inserted into the face plate and the holders are snapped into engage-ment with the mandrels. An additional holder is then snapped onto a respective face plate mandrel and this holder is also welded to the supporting frame. This
- 3 - PHD. 78-065.
additional holder increases the colour selection elec-trode's mechanical stability. During the welding of the additional holder it is also necessary for the colour selection electrode and its already connected holders to be correctly positioned on the mandrels. It is already known that when the mandrels are slightly rough, the holders will not slide correctly on the mandrels. The suggestion has been made to polish the mandrels and to punch the corresponding apertures in the holders so as to be slightly conical to provide a better sliding surface.
However, such steps are very expensive in production line operations.
It has also been established that during flow coating when the individual exposures are made for the red, green and blue phosphors, the snapping of the colour selection electrodes onto the mandrels in the face plate does not occur sufficiently accurately. Differences for each individual exposure operator occur.
Also during the final positioning of the colour selection electrode in the face plate before assembling the tube, special care is necessary. This last step determines how accurately the electron beam of a gun will land on its associated luminescent strips in the finished tube. Although errors in electrode positioning cause beam deviations which are hardly noticeable in the centre of a display screen, considerable deviations are visible in the proximity of the corners.
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additional holder increases the colour selection elec-trode's mechanical stability. During the welding of the additional holder it is also necessary for the colour selection electrode and its already connected holders to be correctly positioned on the mandrels. It is already known that when the mandrels are slightly rough, the holders will not slide correctly on the mandrels. The suggestion has been made to polish the mandrels and to punch the corresponding apertures in the holders so as to be slightly conical to provide a better sliding surface.
However, such steps are very expensive in production line operations.
It has also been established that during flow coating when the individual exposures are made for the red, green and blue phosphors, the snapping of the colour selection electrodes onto the mandrels in the face plate does not occur sufficiently accurately. Differences for each individual exposure operator occur.
Also during the final positioning of the colour selection electrode in the face plate before assembling the tube, special care is necessary. This last step determines how accurately the electron beam of a gun will land on its associated luminescent strips in the finished tube. Although errors in electrode positioning cause beam deviations which are hardly noticeable in the centre of a display screen, considerable deviations are visible in the proximity of the corners.
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- 4 - PHD. 78-065.
From the prior art, jolting tables are known for finding defective contacts during the manufacture of electronic circuits and jolting transporters are known for use during the manufacture of electronic components for transport. In the manufacture of colour television display tubes, jolting of the tube envelope is also known for shaking loose particles out of the mask area so they do not disturb the displayed picture. Typically loose particles such as welding spatters, glass splinters and organic substances occur. These cause clear shadow or colour defects on the display screen during operation of the colour television display tube if they are located in front of the slots in the colour selection electrode.
Tubes having colour purity defects caused by improper frame positioning during manufacture can be corrected afterward only with difficulty.
Thus it is an object of the invention to intro-duce suitable steps in the method of manufacturing a colour television display tube to achieve a better frame positioning accuracy.
In order to sol~e this problem, according to the invention, in a method of manufacturing a colour televi-sion display tube of the kind mentioned in the opening paragraph, an alternating magnetic field is applied in such manner that the parts moved thereby are accurately moved into their desired positions. The alternating magnetic field causes jolting of the parts. As a result of such jolting, the parts each reach a defined final " 1~45813
From the prior art, jolting tables are known for finding defective contacts during the manufacture of electronic circuits and jolting transporters are known for use during the manufacture of electronic components for transport. In the manufacture of colour television display tubes, jolting of the tube envelope is also known for shaking loose particles out of the mask area so they do not disturb the displayed picture. Typically loose particles such as welding spatters, glass splinters and organic substances occur. These cause clear shadow or colour defects on the display screen during operation of the colour television display tube if they are located in front of the slots in the colour selection electrode.
Tubes having colour purity defects caused by improper frame positioning during manufacture can be corrected afterward only with difficulty.
Thus it is an object of the invention to intro-duce suitable steps in the method of manufacturing a colour television display tube to achieve a better frame positioning accuracy.
In order to sol~e this problem, according to the invention, in a method of manufacturing a colour televi-sion display tube of the kind mentioned in the opening paragraph, an alternating magnetic field is applied in such manner that the parts moved thereby are accurately moved into their desired positions. The alternating magnetic field causes jolting of the parts. As a result of such jolting, the parts each reach a defined final " 1~45813
- 5 - PHD. 78-065.
position which can be reliably obtained during subsequent - steps of the tube manufacture. Thus the positioning of the parts during manufacture become independent of the operator and small tolerances are possible.
A method according to the invention is charac-terized in that positioning of the supporting frame with its holders in the face plate and positioning of the mask sheet with respect to the supporting frame, during the manufacture of the colour selection electrode, is effected by the llse of one or more electromagnets which can be actuated with alternating current. These electromagnets are arranged outside the face plate, in the middle of the sides of the supporting frame in such manner that the jolting magnetic field generated thereby moves the parts into their ultimate position in approximately 5 seconds.
A further method according to the invention comprises positioning the colour selection electrode before the connection of the additional holder. Two elec-tromagnets which can be actuated by alternating current are placed in the proximity of the corners of the support-ing frame which are adjacent to the connecting point of the holder. The electromagnets are arranged outside the upright edge of the face plate in such manner that the jolting field generated thereby moves the parts into their ultimate positions in approximately 5 seconds.
Finally, a method according to the invention is characterized in that positioning of the colour selection electrode before the individual ~xposures in the flow 1~4S813
position which can be reliably obtained during subsequent - steps of the tube manufacture. Thus the positioning of the parts during manufacture become independent of the operator and small tolerances are possible.
A method according to the invention is charac-terized in that positioning of the supporting frame with its holders in the face plate and positioning of the mask sheet with respect to the supporting frame, during the manufacture of the colour selection electrode, is effected by the llse of one or more electromagnets which can be actuated with alternating current. These electromagnets are arranged outside the face plate, in the middle of the sides of the supporting frame in such manner that the jolting magnetic field generated thereby moves the parts into their ultimate position in approximately 5 seconds.
A further method according to the invention comprises positioning the colour selection electrode before the connection of the additional holder. Two elec-tromagnets which can be actuated by alternating current are placed in the proximity of the corners of the support-ing frame which are adjacent to the connecting point of the holder. The electromagnets are arranged outside the upright edge of the face plate in such manner that the jolting field generated thereby moves the parts into their ultimate positions in approximately 5 seconds.
Finally, a method according to the invention is characterized in that positioning of the colour selection electrode before the individual ~xposures in the flow 1~4S813
-6- PHD. 78-065.
coating process is effected by the use of two electromag-nets which can be actuated with alternating current.
These electromagnets are advantageously placed in the proximity of the corners of the supporting frame in such a manner that the magnetic jolting field generated by the electromagnets moves the parts into their ultimate posi-tion in approximately 5 seconds. Alternatively, at least two electromagnets may be provided on the spherical side of the face plate in the area above the supporting frame.
The electromagnets are preferably energized with alternating current of approximately 50 Hz.
When using the invention, the distance between the mask sheet and the face plate inner surface can ke maintained with a tolerance of 0.01 to 0.02 mm. This is an improvement, as compared with manual positioning during welding of the additional holder, of up to 20 /um.
Embodiments of the invention are shown in the drawing and will be described in detail hereinafter. In the drawings.
Figure 1 is a plan view of a face plate with inserted colour selection electrode and an electromagnet on its long side.
Figure 2 is a sectional view of critical suspen-sion elements, namely a holder of the colour selection electrode, a mandrel, and a welding connection attaching the mask sheet to the supporting frame.
Figure 3 is a plan view of a face plate with inserted colour selection electrode and two electromagnets il ~58~3
coating process is effected by the use of two electromag-nets which can be actuated with alternating current.
These electromagnets are advantageously placed in the proximity of the corners of the supporting frame in such a manner that the magnetic jolting field generated by the electromagnets moves the parts into their ultimate posi-tion in approximately 5 seconds. Alternatively, at least two electromagnets may be provided on the spherical side of the face plate in the area above the supporting frame.
The electromagnets are preferably energized with alternating current of approximately 50 Hz.
When using the invention, the distance between the mask sheet and the face plate inner surface can ke maintained with a tolerance of 0.01 to 0.02 mm. This is an improvement, as compared with manual positioning during welding of the additional holder, of up to 20 /um.
Embodiments of the invention are shown in the drawing and will be described in detail hereinafter. In the drawings.
Figure 1 is a plan view of a face plate with inserted colour selection electrode and an electromagnet on its long side.
Figure 2 is a sectional view of critical suspen-sion elements, namely a holder of the colour selection electrode, a mandrel, and a welding connection attaching the mask sheet to the supporting frame.
Figure 3 is a plan view of a face plate with inserted colour selection electrode and two electromagnets il ~58~3
- 7 - PHD. 78-065.
on the two narrow sides.
Figure 4 is a plan view of the face plate with two inserted electromagnets in the spherical area.
Figure 5 is a side elevation of Figure 4 partly in cross-section, with two alternatives for the placement of the electromagnets.
Figure 6 is an example of a circuit arrangement for energizing two electromagnets.
Reference numeral 1 in the Figures denotes the upright edge of the face plate of a colour television display tube. Referring to Figure 1, reference numerals 2 denote the suspension points for a supporting frame 3 and mask sheet 4 which collectively form a colour selection electrode 5. During assembly of the colour selection electrode three supporting frame holders are snapped into engagement at 2 and an electromagnet 16 is switched on in order that the inserted supporting frame with its holders, and the mask sheet, find their correct positions. It exerts a pulling force on the supporting frame via the magnetic field. The field lines of the electromagnet 16 emanate approximately perpendicularly from the poles denoted by N and S, as shown at 8, then extend along the supporting frame and close in said frame. When the elec-tromagnet 16 is connected to an alternating line current oscillating at 50 Hz, a vibration of the supporting frame at 100 Hz occurs and the supporting frame is jolted with its holders on the face plate mandrels without the inter-ference of an operator, the ultimate position being achieved after approximately 5 seconds. Simultaneously 114S8~3
on the two narrow sides.
Figure 4 is a plan view of the face plate with two inserted electromagnets in the spherical area.
Figure 5 is a side elevation of Figure 4 partly in cross-section, with two alternatives for the placement of the electromagnets.
Figure 6 is an example of a circuit arrangement for energizing two electromagnets.
Reference numeral 1 in the Figures denotes the upright edge of the face plate of a colour television display tube. Referring to Figure 1, reference numerals 2 denote the suspension points for a supporting frame 3 and mask sheet 4 which collectively form a colour selection electrode 5. During assembly of the colour selection electrode three supporting frame holders are snapped into engagement at 2 and an electromagnet 16 is switched on in order that the inserted supporting frame with its holders, and the mask sheet, find their correct positions. It exerts a pulling force on the supporting frame via the magnetic field. The field lines of the electromagnet 16 emanate approximately perpendicularly from the poles denoted by N and S, as shown at 8, then extend along the supporting frame and close in said frame. When the elec-tromagnet 16 is connected to an alternating line current oscillating at 50 Hz, a vibration of the supporting frame at 100 Hz occurs and the supporting frame is jolted with its holders on the face plate mandrels without the inter-ference of an operator, the ultimate position being achieved after approximately 5 seconds. Simultaneously 114S8~3
- 8 - PHD. 78-065.
the mask sheet 4 is jolted into its force-free rest posi-tion. Only then is the mask sheet welded to the support-ing frame. Automatic welding occurs at 14 (Figure 2) along the circumferences~of the mask sheet and the support-ing frame 1 where the bent edge 13 of the mask sheetoverlaps the adjacent edge 12 of the supporting frame.
Figure 2 also shows one of the holders 11, a part of the upright edge of the face plate 9 and a metal-lic mandrel 10 which is moulded in the glass and on which the holder 11 bears. Said holder is welded to the support-ing frame edge 12 of the colour selection electrode and at one end has an aperture which is placed over a conical part of the mandral. The colour selection electrode always remains detachable from the face plate because it is held only by the resilience of the holder 11.
The supporting frame 12 may have a thicker wall than the mask sheet. This is necessary for so-called frameless masks. In such case it is common to provide the mask sheet 13 with reinforcements and hence produce a mask sheet edge 13 having the same thickness as the frame edge 12, which is favourable from a thermal point of view.
Before the welding of the connections at 14 (up to 10 spot welds are made along the circumferences for a 67 cm colour television display tube) the supporting frame edge 12 with its holder 11 must be positioned on the man-drel 10 in its ultimate rest position. The mask sheet edge 13 must also be accurately positioned on the support-ing frame edge 12. To effect correct positioning of the ,~;
i,. .
~l~S8~3
the mask sheet 4 is jolted into its force-free rest posi-tion. Only then is the mask sheet welded to the support-ing frame. Automatic welding occurs at 14 (Figure 2) along the circumferences~of the mask sheet and the support-ing frame 1 where the bent edge 13 of the mask sheetoverlaps the adjacent edge 12 of the supporting frame.
Figure 2 also shows one of the holders 11, a part of the upright edge of the face plate 9 and a metal-lic mandrel 10 which is moulded in the glass and on which the holder 11 bears. Said holder is welded to the support-ing frame edge 12 of the colour selection electrode and at one end has an aperture which is placed over a conical part of the mandral. The colour selection electrode always remains detachable from the face plate because it is held only by the resilience of the holder 11.
The supporting frame 12 may have a thicker wall than the mask sheet. This is necessary for so-called frameless masks. In such case it is common to provide the mask sheet 13 with reinforcements and hence produce a mask sheet edge 13 having the same thickness as the frame edge 12, which is favourable from a thermal point of view.
Before the welding of the connections at 14 (up to 10 spot welds are made along the circumferences for a 67 cm colour television display tube) the supporting frame edge 12 with its holder 11 must be positioned on the man-drel 10 in its ultimate rest position. The mask sheet edge 13 must also be accurately positioned on the support-ing frame edge 12. To effect correct positioning of the ,~;
i,. .
~l~S8~3
- 9 - PHD. 78-065.
holder with respect to the mandrel and of the mask sheet with respect to the supporting frame, the electromagnet 16 is energized causing a 100 Hz vibration lasting approximately 5 seconds. After this vibration, the parts of the colour selection electrode have reached their ultimate rest positions and the welding may be carried out.
Figure 3 shows a similar electromagnet arrange-ment used for fixing a fourth suspension point 15. In this step of the tube manufacture, the assembled colour selection electrode 5 is snapped into engagement with the face plate 1 at the three places denoted by 2. Only the fourth point at 15 is free. The electromagnets 6 and 7 are then switched on vibrating the colour selection elec-trode with respect to the fixed glass and an ultimate rest position of the electrode is achieved in this case also after approximately 5 seconds and the operator can then weld the additional fourth holder for connection to the fourth point, so that the last point for the connec-tion of the colour selection electrode in the assembled face plate is also fixed.
Figure 4 shows a further electromagnet arrange-ment used during the flow-coating process when the dis-play screen is laid on the inside. During the flow-coat-ing process, three exposure steps are carried out, as is known, because the exposing light source must successively assume different positions for providing the red, green and blue colours. Because chemical treatmentsinvolving phosphor suspensions and water must be used, the colour selection electrode 5 must be removed from the face plate ^ ~-
holder with respect to the mandrel and of the mask sheet with respect to the supporting frame, the electromagnet 16 is energized causing a 100 Hz vibration lasting approximately 5 seconds. After this vibration, the parts of the colour selection electrode have reached their ultimate rest positions and the welding may be carried out.
Figure 3 shows a similar electromagnet arrange-ment used for fixing a fourth suspension point 15. In this step of the tube manufacture, the assembled colour selection electrode 5 is snapped into engagement with the face plate 1 at the three places denoted by 2. Only the fourth point at 15 is free. The electromagnets 6 and 7 are then switched on vibrating the colour selection elec-trode with respect to the fixed glass and an ultimate rest position of the electrode is achieved in this case also after approximately 5 seconds and the operator can then weld the additional fourth holder for connection to the fourth point, so that the last point for the connec-tion of the colour selection electrode in the assembled face plate is also fixed.
Figure 4 shows a further electromagnet arrange-ment used during the flow-coating process when the dis-play screen is laid on the inside. During the flow-coat-ing process, three exposure steps are carried out, as is known, because the exposing light source must successively assume different positions for providing the red, green and blue colours. Because chemical treatmentsinvolving phosphor suspensions and water must be used, the colour selection electrode 5 must be removed from the face plate ^ ~-
-10- PHD. 78-065.
during each treatment. It is repeatedly removed from the face plate and snapped into engagement during the exposure steps. Considerable differences in the posi-tion of the colour selection electrode arise during such repeated replacement in the face plate. According to the invention two electromagnets are provided on either the spherical part of the face plate or the back of the electrode, as is shown in Figures 4 and 5, respectively, such that the fields of said magnets impinge perpendicularly on the electrode and close it.
When the electromagnets are energized, a vibration occurs which is sufficient to move the holders to their rest positions.
Figure 6 shows an example of a circuit arrange-ment which can be utilized to energize the electromag-nets. An alternating current of 220 V/50 Hz can be applied to the terminals 21 and 22. An isolating trans-former 23 has outputs which are electrically connected to the electromagnets 6 and 7 via rectifiers 24 and 25.
Thus the electromagnets are energized by opposite phases and attract the mask sheet and the supporting frame at 50 Hz causing these parts to vibrate and move to their correct position.
during each treatment. It is repeatedly removed from the face plate and snapped into engagement during the exposure steps. Considerable differences in the posi-tion of the colour selection electrode arise during such repeated replacement in the face plate. According to the invention two electromagnets are provided on either the spherical part of the face plate or the back of the electrode, as is shown in Figures 4 and 5, respectively, such that the fields of said magnets impinge perpendicularly on the electrode and close it.
When the electromagnets are energized, a vibration occurs which is sufficient to move the holders to their rest positions.
Figure 6 shows an example of a circuit arrange-ment which can be utilized to energize the electromag-nets. An alternating current of 220 V/50 Hz can be applied to the terminals 21 and 22. An isolating trans-former 23 has outputs which are electrically connected to the electromagnets 6 and 7 via rectifiers 24 and 25.
Thus the electromagnets are energized by opposite phases and attract the mask sheet and the supporting frame at 50 Hz causing these parts to vibrate and move to their correct position.
Claims (9)
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of positioning a supporting frame for a colour television tube mask in a repeatedly obtainable rest position with respect to the face plate of the tube to facilitate a tube manufacturing process requiring such positioning, said method comprising the steps of:
A. attaching the supporting frame to the face plate by engaging holders provided on the frame with respective frame-locating members provided on the face plate; and B. applying a time-varying electromagnetic field to the frame until said holders and their respective frame locating members are vibrated into ultimate rest positions relative to each other.
A. attaching the supporting frame to the face plate by engaging holders provided on the frame with respective frame-locating members provided on the face plate; and B. applying a time-varying electromagnetic field to the frame until said holders and their respective frame locating members are vibrated into ultimate rest positions relative to each other.
2. A method as in claim 1 which is utilized to facilitate attachment of the mask to the supporting frame, said method further comprising the steps of:
A. placing the mask in its approximate rest position in the face plate before attaching the support-ing frame to the face plate;
B. applying the time-varying magnetic field to the mask until it is vibrated into an ultimate rest posi-tion relative to the face plate; and C. attaching the mask to the supporting frame.
A. placing the mask in its approximate rest position in the face plate before attaching the support-ing frame to the face plate;
B. applying the time-varying magnetic field to the mask until it is vibrated into an ultimate rest posi-tion relative to the face plate; and C. attaching the mask to the supporting frame.
3. A method as in claim 2 where the time-varying magnetic field is produced by an electromagnet placed PHD. 78-065.
adjacent a side wall of the face plate.
adjacent a side wall of the face plate.
4. A method as in claim 1 which is utilized to facilitate the connection of an additional holder to the supporting frame, said method further comprising the steps of:
A. engaging the additional holder with a respec-tive frame-locating member provided on the face plate; and B. connecting the additional holder to the supporting frame after applying the time-varying electro-magnetic field;
said field being applied by electromagnets placed adjacent the face plate on opposite sides of the additional holder.
A. engaging the additional holder with a respec-tive frame-locating member provided on the face plate; and B. connecting the additional holder to the supporting frame after applying the time-varying electro-magnetic field;
said field being applied by electromagnets placed adjacent the face plate on opposite sides of the additional holder.
5. A method as in claim 1 where the mask is already attached to the supporting frame and where the method is utilized to facilitate successive exposures and chemical treatment of colour phosphors on the face plate, said exposures being made through apertures in said mask.
6. A method as in claim 5 where the time-varying electromagnetic field is produced by electromagnets placed adjacent the face plate and arranged such that the field impinges perpendicularly on the mask.
7. A method as in claim 5 where the time-varying electromagnetic field is produced by electromagnets placed adjacent the supporting frame and arranged such that the field impinges perpendicularly on the mask.
8. A method as in claim 3, 4 or 6 where said elec-tromagnets are energized by a 50 Herz alternating current PHD. 78-065.
to produce the time-varying magnetic field.
to produce the time-varying magnetic field.
9. A method as in claim 7 where said electromag-nets are energized by a 50 Herz alternating current to produce the time-varying magnetic field.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2822345A DE2822345C3 (en) | 1978-05-22 | 1978-05-22 | Method of inserting a color selection electrode into a color television picture tube |
| DEP2822345.2 | 1978-05-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1145813A true CA1145813A (en) | 1983-05-03 |
Family
ID=6039962
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000327937A Expired CA1145813A (en) | 1978-05-22 | 1979-05-17 | Method of manufacturing a colour television display tube |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0005567B1 (en) |
| JP (1) | JPS54155760A (en) |
| CA (1) | CA1145813A (en) |
| DE (2) | DE2822345C3 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2471040A1 (en) * | 1979-12-04 | 1981-06-12 | Videocolor | Automatic assembly for leaf spring mounted TV masks - uses movable mask and screen supports with cams for springs to and from screen mounts |
| DE3540494A1 (en) | 1985-11-15 | 1987-05-21 | Phoenix Ag | SEALING PROFILE FOR TUNNEL TUBE SEGMENTS |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL6614551A (en) * | 1966-10-15 | 1968-04-16 |
-
1978
- 1978-05-22 DE DE2822345A patent/DE2822345C3/en not_active Expired
-
1979
- 1979-05-03 DE DE7979200214T patent/DE2962778D1/en not_active Expired
- 1979-05-03 EP EP79200214A patent/EP0005567B1/en not_active Expired
- 1979-05-17 CA CA000327937A patent/CA1145813A/en not_active Expired
- 1979-05-21 JP JP6255479A patent/JPS54155760A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54155760A (en) | 1979-12-08 |
| DE2822345B2 (en) | 1980-04-17 |
| EP0005567B1 (en) | 1982-05-12 |
| EP0005567A2 (en) | 1979-11-28 |
| JPS6131937B2 (en) | 1986-07-23 |
| EP0005567A3 (en) | 1979-12-12 |
| DE2822345A1 (en) | 1979-11-29 |
| DE2962778D1 (en) | 1982-07-01 |
| DE2822345C3 (en) | 1981-01-22 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |